First, Blender’s Undo system has been inproved, but still has some problems. Blender uses RAM for a lot of it’s undo steps. It use to use only RAM. So when you’re working with high poly count objects this would crash Blender after doing a few things, because of running out of memory.
Second, if this is the case for you then you can fix this by going to preferences system and set the undo memory limits. By setting this Blender won’t use more than that. This means that you may not get as many undo steps(The option above memory limit) because you hit the memory cap.
Third, This causes me problems and I don’t know if this will effect you, but you can try it. Under preferences viewport, Turn off GPU for Selection and/or Subdivision. Note: Technically speaking by computer doesn’t meet the minimum requirements for Blender since 3.3. I’m sure the only reason that it still works is because I’m using Linux.
