PLA keeps cracking around threaded inserts - any fix?

I'm printing PLA prototypes with threaded inserts for M3 screws. Used different settings like lower infill and slower print speed, but cracks still appear around inserts when I press them in with a soldering iron. Even tried pre-heating inserts and using thicker walls. Cracking happens right at the edge of the hole. Any tricks to avoid this?

#MedicalDevices# #Aerospace# #Prototype#