Inconsistent Turns with EZ-Template

Over the past week, our team switched to PROS with EZ-Template to improve our autonomous consistency and to add few other features down the road that we would not be able to complete in VEXcode python (our previous coding software).
After spending time getting code working, tuning PID constants, and building a small autonomous library, we moved on to writing some autons. But when we did, the PID turn functions would not consistently spin to the same heading every run, varying ±15 degrees of rotation. This would only happen when we would do an autonomous routine, not when we did individual turns.
We thought it was maybe a quirk of PROS so to make sure we had autonomous code for our upcoming tournament, wee switched back to VEXcode python but had the same issue with code we had no problems using for the past two years.
We expected it to be a hardware problem, and tried changing everything. The brain, inertial sensor, wire, port, yet nothing worked to fix the issue. Any inertial code on either softwares when included in an autonomous routine would turn differently every run.
If anyone could help diagnose the issue, that would be really helpful. I can answer any questions and have included my PROS code folder in a Google drive link below.