How to fix macOS Big Sur Dock after having customised it on Catalina for uBar
I executed commands from this HowToGeek article to reset the Dock and restarted the Mac; which didn't help (yet). I had used both the commands - &quot;The Simple Fix&quot; killall Dock and &quot;The Slightly Less Simple Fix&quot; defaults delete com.apple.dock; killall Dock.
Then I relaunched the Finder as recommended in the same article and now I'm back to my fantasy setup.
Sorry for the bother, I hope this helps others as well. I had to set preferences for dock again. On Big Sur we no longer need to follow the Terminal commands from the Ask Different question mentioned above.