dragging keywords under parent no longer works

I'm no longer able to drag a newly made keyword to a parent, after starting C1pro 22  I can click and drag the keyword but after release while hovering on intended parent keyword nothing happens. After a while I'm not even able to drag the keyword. Started(I think) after latest update(on 15.3.2.12). Using up to date windows 10 pro 21H2  built 19044.1889 . Already submitted a request for support but so far no answer. Anybody here an idea?

Already processed a larger number of photo's in latest update so reverting to earlier version not an option.