Backrest with Rclone not working since 1.9.0

[MrSlumber]

Hi,
great fan of Backrest and it really rescued my files once so I was more than happy to donate for this fantastic project! :-)

Been running the Backrest Docker container in Unraid for over a year now with the "rclone:myconfig:repository" repository URL option and it worked flawless with Nextcloud storage via WebDAV via Rclonewith with no hickups.

But since version 1.9.0 and 1.9.1 everything seems to be broken, no backups, prunes or checks are possible any more.
I changed nothing in Unraid, Nextcloud or somewhere else just updatet the Backrest Docker container like before.

E.g. when I start a backup task which worked perfectly via cron for over a year now the following errors messesages are returned, please look at the bottom of this post.

I'm in no way into programming but skilled enough (I think ;-) ) to get the Unraid Backrest Docker Container running with the Rclone option for Nextcloud but really got no clue what the errors messages mean or where I should look.
Tried everything from reboot to reinstall but still the same. When I try to access the Restic/Backrest repository in Nextcloud via "Nacho-Rclone-Native-GUI" Docker container there is no problem.

So bear with my knowledge and thanks in advance for looking at my problem and for troubleshooting.

Keep up the good work!

error message:

error: failed to get snapshots for plan: get snapshots for plan "unraid-full-backup-nextcloudrestic": command "/bin/restic snapshots --json -o sftp.args=-oBatchMode=yes --tag plan:unraid-full-backup-nextcloudres..." failed: exit status 1 Output: rclone: 2025/08/11 02:20:32 ERROR : locks/df1e54c6313b6ab491abb18260be2a1e9ba748806fda0b15be99a03121b5aa0a: Post request put error: A type error occurred. For more details, please refer to the logs, which provide additional context about the type error.: TypeError: 500 Internal Server Error rclone: 2025/08/11 02:20:32 ERROR : locks/df1e54c6313b6ab491abb18260be2a1e9ba748806fda0b15be99a03121b5aa0a: Post request rcat error: A type error occurred. For more details, please refer to the logs, which provide additional context about the type error.: TypeError: 500 Internal Server Error Save(<lock/df1e54c631>) returned error, retrying after 581.654546ms: unexpected HTTP response (500): 500 Internal Server Error rclone: 2025/08/11 02:20:42 ERROR : locks/df1e54c6313b6ab491abb18260be2a1e9ba748806fda0b15be99a03121b5aa0a: Post request put error: A type error occurred. For more details, please refer to the logs, which provide additional context about the type error.: TypeError: 500 Internal Server Er ... 12652 bytes truncated ...