I just spent three hours trying to update the firmware on my Dell dock from a Linux environment. Solution: quietly weep, revert to Windows (for a few minutes to run the .exe from Windows boot disk).
Before anyone starts trying to troubleshoot it, yes, I tried all the things in fwupdmgr. Even went so far as to install snap because Dell’s Linux tool required it, and that failed as well.
Next time, you’ll know to check the fwupd database before a purchase.
Can’t tell if serious
The updates for Dell docks are in that database. They just fail most of the time. Dell told people to power cycle the dock and closed the issue on GitHub.