PBX services Stops automatically

Hi Team,

We have NBU 7.6.0.3 running with 6 media servers , all are of same version. Recently we could observe PBX services are automatically stopping atleast once a week

We are not sure on what is the cause of this issue, if we start only the PBX services all backups are running again.

Have you heard any bug regading this??? can you tell me how to approach and narrow down the issue.

changes made on past 3 months - Added 3 Media servers and 2 Datadomains, backups are running fine on all those