NCP "HPB-Service” is down after btw during Backup

I am on 1.55.3 in a Proxmox-VM with 8 GB-Ram
“HPB service is down.” always occurs after the autobackup which is made to a mounted share on my NAS. About 57 GB should be backed up. When this happens, NCP is in maintenance mode. If you deactivate this and then run “clear-php-opcache”, the HPB service runs again and the backup works. Any ideas? @theCalcaholic

Similar to here NextcloudPi: HPB-Service is down