Big Sur update ll.2.2 will not down load to the 11.2.1 version on my desk top

Are there any AntiVirus, Disk Cleaner, Optimizers, Defrag, VPNs etc installed which should be removed as per Developers Instructions. They are useless, unneeded, cause havoc and interfere with the normal operation of the OS. The Built-in Security of Big Sur is all that is required. If this does Not Apply - Disregard

If doing over wifi - it is very iffy but doable. Better results via Ethernet connection.

If over Ethernet is used, suggest Shutdown Router. Shutdown computer. Restart Router then same to computer but hold Shift Immediately at startup. Safe Mode does a Repair Disk, clears cache files and only load Apple Software and fonts - loads slowly - Normal. Try again.

If over Wifi - same as ethernet Router and computer restart and Safe Mode except disconnect ALL Other devices using the Wifi - want Max Bandwidth to this computer and try again.

There is no reason to ever install or run any 3rd party "cleaning", "optimizing", "speed-up", anti-virus, VPN or security apps on your Mac.  This user tip describes what you need to know and do in order to protect your Mac: Effective defenses against malware and other threats - Apple Community   

I found a better way to get the Big Sur updates is to go to the App Store, search for Big Sur and download from there and install.

Same here. Gets stuck with 10 minutes to go.

Cancelled it myself.

Mine went through on second attempt, it stayed at 10 minutes for a while but the blue line was moving and eventually rebooted fine.