Control Room Settings are frequently erased

[Reco29]

Hi, have a look at this thread.

Custom Control Room preset option dissappeasred overnight

Cubase automatically creates one (and only one ) Default Control Room preset, which stores the settings of the last session. These settings are re-applied the next time the application is started. The enormous number of Default presets in your list is unusual. You can delete them manually in Audio Connections - Control Room. Or, if you are familiar with editing XML files, you can edit the ControlRoomPresets.pxml file accordingly. Preset objects begin with <obj class="FPreset" ID="[number…

@ASM proposed and tested a different approach which suggests to write-protect the pxml instead of doing a backup and replace it.
Do you still have previous Cubase versions on your system, too?