Yeah I have seen this a bunch of times as well. Especially with deprecated function calls. It generates a bunch of code. I get deprecation warnings. I fix them. Copilot fixes them back. I have to explicitly point out that I made the change for it to not reintroduce the deprecations.

I guess that while code that compiles is easier to train for but code with warnings less so?

I remember there are other examples of changes that I have to tell the AI I made to not have it change it back again, but can't remember any specific examples.