Did you let Duplicati do an automatic upgrade, or did you install new qnapclub QPKG?
What sort of earlier Duplicati versions were run? Do you know if you ran them as root?
On some NAS systems, root user has little space, and many updates may fill partition. Downgrading / reverting to a lower version shows where Duplicati autoupdates may be.
The -r usually requests a recursive folder search If so, omit that for process searches.
Assuming “keeps showing” means “kept telling me to upgrade”, I think I’ve seen that before although I don’t use autoupdates recently (due to an odd installation). Sometimes a Duplicati restart is needed to get going.
Unfortunately I can’t test (no QNAP). What installation method did you use before, and any idea how long? 22.214.171.124_canary_2021-03-10 had extremely little change from 126.96.36.199, but did install methods change?
Even if you install the same way repeatedly, you can also eventually fail due to space (as was mentioned).
Also mentioned was where updates might be, and how to downgrade, e.g. was previous Canary working?
Is there a way to ask a QNAP to restart a service such as Duplicati? If all else fails, reboot might restart it.
Testing from a shell is an option, but for usual backup you’d have to guess a bit at setting the right options.
Other Command Line Utilities has a lot of things to try, but some raise that issue of having to match what existing backup has, but you can’t go into the GUI and export the job config now to test command line run.
If you know what user your Duplicati usually runs as (you can guess based on whether it has root access) then if you can’t start the service in the usual way, you can start it manually (running as the same user) by duplicati command (unless the QNAP packagers changed that), and then browse to port 8216 (odd but maybe QNAP packagers changed it) or port 8200. I guess you can try that even now. What’s at port 8200?
For that matter, is there a mono running or not (ps testing again). If no mono, no Duplicati running, for sure.
Back to command line, you can quickly sanity-check your install with something like duplicati-cli help