[9.004-34] Computer roll back in Default-Group

In the last weeks, we have somethimes 1 computer, which switched back in the default group, withou doing anything.
Normaly i open the default group and delet them. Look at the EP overview the Computer is correclty back in their Group, e.g. "Outside Clients".

Today more than 15 Computers was in the default group. I do the same, go to Groups, edit the Default-Group and delete them all. After safeing and klick in the EP overview, now all correct in the different Groups. :confused:

Anybody where had the same? (Computer roll back to default-group)