MS CE 16.1 German - Cleanup window doesn't show

Just "voluntarily" upgraded from Powerdraft CE 14 to full Microstation CE 16.1 with a clean install (made all user settings from scratch) on latest Windows 10 and still running into the same problem:

When pressing on the file cleanup button the tool window doesn't show. I have a key assigned to "mdl load cleanup;cleanup do;cleanup window close" which works but it always says no duplicates were erased. The window shows for a fraction of a second the first time I execute this command and then won't show again. So I can't check if the settings are correct.

I also installed Microstation v8i SS10 and when doing the file cleanup in my current file it finds more than 2.000 duplicates vs. nothing in CE. Same behaviour in DGNs and DWGs.

What's going wrong here? Had the same behaviour in Powerdraft CE 14 before, so it might be a general setting.