"Undo" only working on track 2 to 8

[Per Boysen]

I'm in contact with a user that has this weird issue that Undo only works when Track 1 is selected. If any of the tracks 2 to 8 is selected Undo does not work. I am mystified. Has anyone seen this issue? What mistake in settings can cause this?

[Jeff]

Check the "Max Undo" parameter in the preset. Usually this is zero
to mean "infinite" but if this is a small number we'll only keep that
many undo layers. If this is 1 or 2 it may appear that undo isn't working.