Scheduled Backup Mgr problem to apply settings

[Brujo]

Usualy I have a scheduled weekly Backup only within the Configuration and the other 2 settings for mail and userdata disabled. However It seems this got broken and I cant disable this both anymore. As soon as i disable both and apply settings both checkmarks are enabled again. I am able just to disable one of this, doesnt matter if it is mail or user and then I can apply it, but not both. Thats wired becaus this was working a long time and from one day to the other it got broken and I had now a lot of Domains which are overused because a full backup was done :-(

Any hints on this?

Plesk 12.5.30 Update #17 on Centos 6.7