Don’t know the reason for that, but just mentioning that I have a PR to change the Jottacloud backend to use a newer upload API, same as currently used by rclone and probably jotta-cli: Jottacloud upload implementation changed to use new api by albertony · Pull Request #4715 · duplicati/duplicati · GitHub. I’ve left it as a draft for quite some time, because I don’t want to complete it until the authentication issues are out of the way (and also until I see that it is worth investing more of my time on it, i.e. other completed PRs actually gets merged and released).