Forge problems

I’ve been making a couple maps in forge and have been having some glitches happen.
First is that sometimes (especially when in smaller areas) I end up clipping through the map or other object.
Second is that out of nowhere my movement snap changes on its own. I’ve had it change to anything from .0001 to 4. There doesn’t seem to be a reason or pattern but I thought I should put it out there.
Hoping for a fix, thanks