I have the following panel dataset of number of workers on online websites ( such as freelancer, Upworks) for each country and occupation type. The dataset is in long format. See below for an example of the dataset. The problem I am facing is that there are repeated observations within a country in one time period for different occupations. Even though I am using an m:1 merge on key variables country timestamp, stata is generating unmatched observations. I have checked that for the unmatched observations the data IS NOT missing in the using dataset. Why is m:1 merger on key variables not working in this case? Are there any other solutions? Any suggestions would be much appreciated. Thanks in advance!

Code:
* Example generated by -dataex-. To install: ssc install dataex
clear
input str10 timestamp str30 country str35 occupation float num_workers int num_projects
"2017-06-16" "Afghanistan"                    "Writing and translation"               12   0
"2017-06-16" "Albania"                        "Clerical and data entry"               14   0
"2017-06-16" "Albania"                        "Creative and multimedia"               42   0
"2017-06-16" "Albania"                        "Software development and technology"   68   0
"2017-06-16" "Albania"                        "Writing and translation"               20   0
"2017-06-16" "Algeria"                        "Clerical and data entry"               12   0
"2017-06-16" "Algeria"                        "Creative and multimedia"               74   0
"2017-06-16" "Algeria"                        "Sales and marketing support"           33   0
"2017-06-16" "Algeria"                        "Software development and technology"   26   0
"2017-06-16" "Algeria"                        "Writing and translation"               36   0
"2017-06-16" "Argentina"                      "Clerical and data entry"               14   0
"2017-06-16" "Argentina"                      "Creative and multimedia"              433   1
"2017-06-16" "Argentina"                      "Sales and marketing support"           18   0
"2017-06-16" "Argentina"                      "Software development and technology"   99   2
"2017-06-16" "Argentina"                      "Writing and translation"              134   0
"2017-06-16" "Armenia"                        "Creative and multimedia"               66   0
"2017-06-16" "Armenia"                        "Software development and technology"   71   4
"2017-06-16" "Australia"                      "Professional services"                 12   0
"2017-06-16" "Australia"                      "Creative and multimedia"              192   1
"2017-06-16" "Australia"                      "Sales and marketing support"          148   0
"2017-06-16" "Australia"                      "Software development and technology"  262   5
"2017-06-16" "Australia"                      "Writing and translation"              152   0
"2017-06-16" "Austria"                        "Clerical and data entry"                8   0
"2017-06-16" "Austria"                        "Professional services"                 22   0
"2017-06-16" "Austria"                        "Sales and marketing support"            2   2
"2017-06-16" "Austria"                        "Software development and technology"   36   0
"2017-06-16" "Austria"                        "Writing and translation"               11   0
"2017-06-16" "Azerbaijan"                     "Creative and multimedia"               26   0
"2017-06-16" "Azerbaijan"                     "Software development and technology"   28   0
"2017-06-16" "Azerbaijan"                     "Writing and translation"                5   0
"2017-06-16" "Bahamas"                        "Professional services"                 14   0
"2017-06-16" "Bahrain"                        "Software development and technology"   14   0
"2017-06-16" "Bangladesh"                     "Clerical and data entry"             1739   9
"2017-06-16" "Bangladesh"                     "Professional services"                585   5
"2017-06-16" "Bangladesh"                     "Creative and multimedia"             5798  96
"2017-06-16" "Bangladesh"                     "Sales and marketing support"         9639 100
"2017-06-16" "Bangladesh"                     "Software development and technology" 5046  37
"2017-06-16" "Bangladesh"                     "Writing and translation"              734   1
"2017-06-16" "Barbados"                       "Sales and marketing support"           24   0
"2017-06-16" "Belarus"                        "Creative and multimedia"               14   0
"2017-06-16" "Belarus"                        "Software development and technology"   13   0
"2017-06-16" "Belarus"                        "Writing and translation"               12   0
"2017-06-16" "Belgium"                        "Professional services"                 14   0
"2017-06-16" "Belgium"                        "Creative and multimedia"               14   0
"2017-06-16" "Belgium"                        "Software development and technology"   42   0
"2017-06-16" "Belgium"                        "Writing and translation"               38   0
"2017-06-16" "Belize"                         "Clerical and data entry"               12   0
"2017-06-16" "Belize"                         "Professional services"                 12   0
"2017-06-16" "Belize"                         "Writing and translation"               12   0
"2017-06-16" "Bhutan"                         "Creative and multimedia"               14   0
"2017-06-16" "Bosnia and Herzegovina"         "Creative and multimedia"              115   0
"2017-06-16" "Bosnia and Herzegovina"         "Writing and translation"               14   0
"2017-06-16" "Brazil"                         "Clerical and data entry"               26   0
"2017-06-16" "Brazil"                         "Professional services"                 14   0
"2017-06-16" "Brazil"                         "Creative and multimedia"              211   0
"2017-06-16" "Brazil"                         "Sales and marketing support"           14   0
"2017-06-16" "Brazil"                         "Software development and technology"  175   0
"2017-06-16" "Brazil"                         "Writing and translation"              243   0
"2017-06-16" "British Virgin Islands"         "Software development and technology"   14   0
"2017-06-16" "Bulgaria"                       "Clerical and data entry"               26   0
"2017-06-16" "Bulgaria"                       "Professional services"                 59   0
"2017-06-16" "Bulgaria"                       "Creative and multimedia"              275   1
"2017-06-16" "Bulgaria"                       "Sales and marketing support"          105   1
"2017-06-16" "Bulgaria"                       "Software development and technology"  200   4
"2017-06-16" "Bulgaria"                       "Writing and translation"               67   1
"2017-06-16" "Cambodia"                       "Creative and multimedia"               14   0
"2017-06-16" "Cambodia"                       "Software development and technology"   14   0
"2017-06-16" "Cameroon"                       "Clerical and data entry"               38   1
"2017-06-16" "Cameroon"                       "Sales and marketing support"           36   0
"2017-06-16" "Cameroon"                       "Software development and technology"   23   0
"2017-06-16" "Cameroon"                       "Writing and translation"               55   0
"2017-06-16" "Canada"                         "Clerical and data entry"              170   0
"2017-06-16" "Canada"                         "Professional services"                102   0
"2017-06-16" "Canada"                         "Creative and multimedia"              696   5
"2017-06-16" "Canada"                         "Sales and marketing support"           94   0
"2017-06-16" "Canada"                         "Software development and technology"  931  19
"2017-06-16" "Canada"                         "Writing and translation"              640   4
"2017-06-16" "Chile"                          "Clerical and data entry"               14   0
"2017-06-16" "Chile"                          "Creative and multimedia"               14   0
"2017-06-16" "Chile"                          "Sales and marketing support"           14   0
"2017-06-16" "Chile"                          "Software development and technology"   18   0
"2017-06-16" "Chile"                          "Writing and translation"               97   1
"2017-06-16" "China"                          "Creative and multimedia"               80   0
"2017-06-16" "China"                          "Sales and marketing support"           12   0
"2017-06-16" "China"                          "Software development and technology"  229   0
"2017-06-16" "China"                          "Writing and translation"              178   1
"2017-06-16" "Colombia"                       "Professional services"                 12   0
"2017-06-16" "Colombia"                       "Creative and multimedia"               38   3
"2017-06-16" "Colombia"                       "Writing and translation"               54   0
"2017-06-16" "Congo, the Democratic Republic" "Writing and translation"               12   0
"2017-06-16" "Costa Rica"                     "Professional services"                 12   0
"2017-06-16" "Costa Rica"                     "Creative and multimedia"               13   0
"2017-06-16" "Costa Rica"                     "Sales and marketing support"          349   1
"2017-06-16" "Costa Rica"                     "Software development and technology"   24   0
"2017-06-16" "Costa Rica"                     "Writing and translation"               12   0
"2017-06-16" "Croatia"                        "Clerical and data entry"               12   0
"2017-06-16" "Croatia"                        "Creative and multimedia"              116   3
"2017-06-16" "Croatia"                        "Sales and marketing support"           48   0
"2017-06-16" "Croatia"                        "Software development and technology"   92   0
"2017-06-16" "Croatia"                        "Writing and translation"               48   0
end