I don’t pay for the service but it seems like about 12 of 15 players that were 5.xx in my area are now 4.xx.
going from 4.9 to 5.1 is normal/common, especially if they are playing alot and/or their opponents are playing alot...
IMO that's not a big change... and in my mind, would be normalized to ~5.0
my previous comment was referring to scenarios where someone's utr is going from utr8 to utr5 and back to utr8 (or generally >1.0 difference is to me a "big" fluctuation...)
but to you 4.x to 5.x might appear "big"
I’m not sure if the women’s ratings dropped as well.
mixed ratings are crap shoot... there's alot of "gentleman rules" being followed in mixed (eg. don't bash the weak player at net)
In 3 years I think WTN will be my pick as the most informative rating system for adult rec players. It already makes the most sense based on the results I see when playing in social leagues with players.
i'd love to see WTN take over... and it's free

but utr is the standard for college.