When i did an initial 65gb backup from an external USB 2.0 drive to a local Ubuntu box via SFTP, the progress bar showed very low transfer rates around 15 KB/s. When I came back after an hour the transfer had frozen so I tried pausing and resuming, but Duplicati had nothing to resume. The backup was listed as never run.
However, after restarting the browser, the backup was listed as completed in just about an hour, and it works fine - I can add and restore files from it. So the UX had frozen somehow.
This never happens when I do backups from internal SSD:s, so I’m guessing it has to do with the USB drive?