The setting WAS 'Disabled', but enabling (+apply) and disabling (+apply) did the trick!!!!

Thx, all is well again!!

Had to redo Dexpot after another program I tried out, messed it up. Everything is now back as it was, with one very important exception: f.i. I have moved several windows of my browser to their specific desktops (grouped by main subject) , However they all still show in the taskbar on every desktop....