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.
depends on the device, but i have a VM just for this purpose. the device passes through to the VM and i update the firmware from there.