After 2 weeks i find the solution.
In my situation the Policy retention was not working correctly.
I get warning that some folder on exchange could not be removed.
But my retention is 7 Days so snapcenter should not delete the log every day.
Normaly i used chrome or firefox to connect to snapcenter console.
Solution for me: i login to snapcenter console direct on Server and redeploy the resource group and also the settings . by both i wait 5 second betwenn next click on next button. So after that policy is working corectly i have 7 day up to minute logs and also delete is happend without warning.