I wonder if you've been caught by something that got me in my early printing days... relative and absolute movements on the extruder.
I would feed say 100mm of filament, then call for 2.5mm of retraction. Instead of just winding back a little bit, it would take the filament right out of the extruder! Let's say that you start from an initial position of 0 steps, call for 1000 steps on the extruder motor, then call for 25 steps of retraction. In relative mode the extruder would just count back 25 steps. If you're in absolute mode then it take the extruder back 975 steps, to extruder position of 25. A long-winded way of saying that the extruder should be relative mode!
In other words, you need an M83 command somewhere in your startup code... "set extruder to relative mode".
Note: I've typed this on the spur of the moment so, if anyone knows better, please correct me!
I'll correct myself! Absolute v. relative is likely to be your problem, but my commands are wrong. I suggest that you take advice from someone who's more up to date than me (it's been a few years since I hit this problem).
Edited 1 time(s). Last edit at 03/04/2022 09:25AM by David J.