Backup session aged out from vproxy - Networker 18.2

Hi everyone ,

we keep having this error in vbackupd-engine.log in the vproxy logs : the failed backups are totally randoms and everytime its fails on totally different VMs  :

2019-11-27T11:06:21Z NOTICE: Aging out inactive session BackupVmSessions - 5e22f003-c9bb-4325-8f88-832c572d64ad (10.10.0.100:vm-69) last accessed 2019-11-27 12:01:20.914044416 +0100 CET.
2019-11-27T11:06:21Z INFO: Deleting logfiles of session '5e22f003-c9bb-4325-8f88-832c572d64ad'...
2019-11-27T11:06:21Z TRACE: Deleting log file '/opt/emc/vproxy/runtime/logs/vbackupd/BackupVmSessions-5e22f003-c9bb-4325-8f88-832c572d64ad.log' of session '5e22f003-c9bb-4325-8f88-832c572d64ad'...
2019-11-27T11:06:21Z INFO: File '/opt/emc/vproxy/runtime/logs/vbackupd/BackupVmSessions-5e22f003-c9bb-4325-8f88-832c572d64ad.log' is moved to '/opt/emc/vproxy/runtime/logs/recycle/vbackupd/BackupVmSessions-5e22f003-c9bb-4325-8f88-832c572d64ad.log'.
2019-11-27T11:06:21Z INFO: Deleted log file '/opt/emc/vproxy/runtime/logs/vbackupd/BackupVmSessions-5e22f003-c9bb-4325-8f88-832c572d64ad.log'.
2019-11-27T11:06:21Z INFO: Deleted resource : 10.10.0.100:vm-69 - 5e22f003-c9bb-4325-8f88-832c572d64ad.
2019-11-27T11:06:21Z INFO: BackupVmSessions: Saved resource map to '/opt/emc/vproxy/runtime/state/vbackupd/BackupVmSessions.gob'.
2019-11-27T11:06:21Z INFO: Aged out 1 'BackupVmSessions' sessions, 11 remaining

if anyone had an idea why this is happening and how to fix it and how can we prevent a backup session from aging out can we increase the session time so it cant age out , i would really appreciate your help