Have applied hotfix 4 and appear to have an old issue rear it's less than pleasant head again.
Here is the test:
Draw a simple building.
Select half of it in Plan in a marquee & viewed it in 3D
Place an object and moved a wall
Then back into Plan
Clicked undo and it goes back into 3D view & undoes what was just performed
Then go back into Plan & everything inside the plan is selected.
I recall this was an issue earlier, but has come back to haunt me again.
Same issue in plan only as well.
Try it.
Have a marquee on the plan.
Delete something outside the marque.
Undo.
Everything inside the marquee should now be selected.
Cheers,
Karl Barker.
27" iMac 3.6 Ghz Intel Core i9
32 Gig Ram
Mac OSX 10.14.6
AC 5.5 - AC22 (NZE)