Dear Stata experts,

i am using 2sls to estimate the impact of water quality on health with state 14.
My explanatory variable is binary (safe water =0 , unsafe water= 1) and my Instrument is also binary (community level water quality).
I wanted to plot the first and 2nd stage residuls. The results are like that . Is there any issue for binary variable? I attach the graphs. For height-for-age, outcome variable is binary.

First stage Array ... 2nd Stage HAZ 2nd stage- Diarrhea Array 2nd stage HAZ Array

The coefficient for the first stage and residuals are similar.