It is known issue, we can't find the steps to reproduce it.

@UserSupport Okay thanks.   I can't reproduce it reliably either - it just happens at random.

When I make a number of changes and then use multiple undos, some of the changes will be undone but then it jumps to another sheet in the schematic and starts undoing changes in that sheet.  So I can't make more than a few undos in the first sheet.  I find undo almost unusable because of this.

@mchahn Do you remember any steps to reproduce this issue?

It happens every time I make changes in one sheet, make changes in another sheet, and then try to do muliple undos in the second sheet.  It switches sheets after a few undos.

@mchahn It is will switch sheets to undo.

I understand that, but it switches too early.  If I make 1 change to sheet 1, and then make 10 changes to sheet two, then when I undo five or six changes on sheet 2 it switches back to the change on sheet 1.  The rest of the changes on sheet two can never be undone.  It is quite broken.

I apologize.  It may be redo, not undo, that is broken.  I haven't used it since I posted this and now I don't remember if it was undo or redo.

No undo is broken too. It jumps to a page I edited far more distantly. I guess I don't know how grandular the undo feature is - possibly not every change but snapshots instead - in which case the undo/redo will seem random and useless.