Urbackup delets finished backups after some time

I´ve been monitoring this issue for quiet some time now and i cant get the hang of it as to why Urbackup is deleting already finished Backups. Also Clients and Server that are listed on the Main Menu (Which were Backuped therefore green marked) turn back to red (no current Backup). I couldnt find any info on this topic, maybe someone can link me a thread or provide me with the needed information regarding this topic.

Attached deleting message on Admin Page.

Server runs on Debian 10 and has a total storage of 64TB, if you need futher info regarding the server or setups pls do not hesitate to ask.

thanks in advance

How are your backups setup in terms of intervals for image and file backups, and maximum number of backups?