Groups are missing the member list

Hi

Since a day or max two our "Sensor", "Status" and "Port" Groups are empty, the member number is the same as before but the member list is empty. When trying "Rebuild" an error occurs "WARNING. Possible CSRF attack with EMPTY request token." and when trying to modify a Group "saving" results in "Update Failed." All our "Device" Groups seem to work as before.
We have 24.3.13371 and I have tested in Firefox and Chrome.

Br

//joakim