drag / drop between folders not working

Drag / drop between folders seems to stop working intermittently (Move To menu command still works) Quit / Reopen usually corrects the problem but it rears its ugly head soon enough.

Having same problem across two computers running separate databases so wondering if it could be something to do with the 10.4.10 update recently installed on both. Anyone else having this trouble?

Not a big deal I know but DT hasn’t given the slightest cause for concern before, so little things become disconcerting!

Which product/edition/version and which view do you use?