I have this same problem. Not sure that it's specific to 1903, when googling the problem I've seen it happen to other people after upgrading to 1703 and 1803 (I think).
I've tried rebooting numerous times as DaveM121 suggested with no luck. I also did a system restore to the restore point before the 1903 upgrade, also with no luck.
I've been using my laptop for a few weeks since this happened. Except for being weird, I'm not actually having any problems with all of my user files being in the Rick.000 folder, except for the shortcuts in my Quick access list not working because they were still pointing to my old user files. No problems with opening Recent files in Word or Excel, or any other problems I can think of. So unless someone can come up with a solution soon that actually works, I think I'll just leave things as they are and update my shortcuts. And hope that it doesn't happen again after the next upgrade.