Undo not working in one case

Ran into undo not working. I scaled 1d a few polysurfaces and after a few operations of grouping and ungrouping and moving undo was no longer working on the polysurfaces. Although it worked on the ungroup command before the polysurfaces were scaled and went back to having the items grouped before ungroup command, they still retained the edit made after ungroup.
I didn’t save the file I watch for this one.

Thanks for the report, I’ll try and reproduce it for a bug report. If you get a file where you see this repeatedly with the same steps, please post it with the exact workflow used.