Ever since the 1.13 update, Mac users can't do 2 actions at the same time.

The most prominent bug is shift crouching and using the mousewheelscroll at the same time. It just doesn't scroll, which affects a HUGE part of my gameplay. I've tried rebinding crouch to other keys but they all come with their own problems and I get the same issue.

Even with the latest release, the bug still hasn't been patched yet, and on certain servers that stay on 1.13, the bug will persist until it is fixed. It's been going on for a while now but I don't think this issue has ever been addressed by minecraft developers.