I am seeing the same behavior it seems to occur if I use Firefox to do the initial access of the unRAID dashboard after a server restart. I was able to avoid the popup by using Microsoft Edge Version 101.0.1210.53 (Official build) (64-bit) to initially access the dashboard after a reboot. Now no popup on Firefox or Edge and all appears to be normal.
No popup all is normal
Same problem here too, Failed to connect: Only 'http' and 'https' schemes are allowed. Parameter name: requestUri" when backing up to OneDrive. As woocash suggested rolling back the repository to an older version “linuxserver/duplicati:v2.0.4.23-2.0.4.23_beta_2019-07-14-ls27” resolves.