Welcome to the forum @Chuhtra
How did you do the original install, and how did you update? The AUR packagers had Duplicati run as user duplicati not user root. This throws off a lot of people. Updating Duplicati through Duplicati seems like it will not upset whatever you had before, but I’m not positive the same is true for update using an AUR package.
https://aur.archlinux.org/packages/duplicati-latest/ updated yesterday, so the timing is a little bit suspicious.
Is that typed right? It should be Duplicati not duplicati. Also look in ~duplicati/.config/Duplicati
Installing Duplicati on Linux (Arch / Manjaro) talks about how to edit your systemd unit file if you prefer root.
Another thing that sometimes can happen is you get two copies of Duplicati up. You can look at browser’s URL. If it’s port :8200, that’s the first Duplicati. If it’s :8300 it’s a later second-run copy, and could be empty.
EDIT:
In any Duplicati GUI you can also look at About → System info at UserName to see what user that’s using.