Your description sure sounds like the kind of mangling in the reel that happens as DWThomas says when you don't align it at the start.

I occasionally get a few mangled sprockets from camera. These can contribute to jumping a rail on the reel - which can lead to mangling.

Happens with and without experience. Most of the time it works for me. But as you know, it's fairly easy to "tell" that it happened. Sometimes it will take me several attempts to get it right once I have gone astray. I will unreel and re-start and proceed carefully until it feels right.

And sometimes the first "bad" winding will crimp the film making it more likely, exacerbating the problem.