Hello, I am attempting to the stteffects ipwra in order to study the effect of drug1 on time to death in a retrospective cohort with 10,000 patients (~5k per group).

stset deaddays_90, fail(dead_90==1)

stteffects ipwra ( i.age_cat preop_hbga1c i.insurance_type_simple i.smoking hx_chf hx_anemia i.hospital i.asacat3 dispo_simple i.proc_type_short healthyuser_pcp_last365_bin)(drug1 c.age##rx_insulin bmi female asa i.insurance_type_simple hx_pe hx_dvt hx_afib hx_copd hx_anemia hx_cad hx_oa hx_htn hx_cancer hx_asthma hx_gerd hx_depression hx_stroke hx_pvd hx_chf rx_betablocker rx_diuretic rx_ccb rx_statin rx_insulin preop_hbga1c rx_asa rx_coumadin rx_antiplt healthyuser_mamo_all healthyuser_pcp_last365_bin healthyuser_colonoscopy i.race) if fullcohort_rosey==1, vce(robust)

However, I believe I am having issues with convergence (I have been up to a thousand iterations w/o the EE criterion changing or getting an output).
Iteration 91: EE criterion = 1.368e-16 (not concave)
Iteration 92: EE criterion = 1.368e-16 (not concave)

Just looking at variables in logit or probit model, only requires 4 iterations. I have also tried taking out nearly all of the variables for bare-bones model testing and ma having the same problem.

stteffects ipwra (age preop_hbga1c )(drug1 age) if fullcohort_rosey ==1, vce(robust)

Any help or guidance would be greatly appreciated!!