Undo + Multiresolution | What am I doing wrong?

Hello, I’m new to Nomad Sculpt and 3D sculpting in general (just started tonight). So maybe this is a simple fix and I’m just lost.

I lowered the multiresolution so I could simplify what I was working on. Once I got the basic shape I wanted, I started to create holes for the eyes, and then I raised the resolution to see how it looked. I decided to undo the eyes by using the bottom back arrow a few times, of course. This took away the eyes and sent me back to the lower resolution I was at before. But now when I go to raise the resolution, all my previous work (the eye holes) that should be gone comes back. So is it the app that’s not working right or am I doing something wrong?

By the way I’m using the most up-to-date version on an IPad Pro. Thank you for any help.

So I think I have already figured it out… I have to go down to the lower resolution and hit “Delete Higher” and then hit “Subdivide” to bring back the option for higher resolutions without the pervious data. I’m sure this is probably how it’s meant to be and has its uses, but as a beginner it feels like unnecessary steps or a feature that shouldn’t work that way by default. It caused a lot of frustration, but you live and you learn I guess.

I hope I’m correct here. I’ll leave this in case I’m wrong, or maybe I’m right and it’ll help someone else who’s brand new like me.