Filen Desktop with Borg cannot write randomly

[lawmanuk]

Describe the bug
Adding here as no issues option in filen desktop.
When using vorta borg on debian testing, after uploading a few gig, get error as per screenshot

To Reproduce

1. mount filen with linux desktop on debian testing (or sparky testing)
2. create borg repository on filen
3. Try to backup local data to filen via vorta borg

Expected behavior
backup without errors

Logs/Screenshots
desktop screenshot added

System (please complete the following information):

• OS: Sparky testing linux (based on debian testing)
• hardware configuration (e. g. ryzen 5 CPU, 40 gb RAM, 500gb Disk)
• filesystem and disk type used (e. g. ext4)

Additional context
filen is giving me constant problems for weeks uploading, whether via rclone, or desktop mount.