Rating Adjustments

I've seen it happen a few times, so now I'm curious. Every once in a while I'll win a game, and I get my eight points, as usual. But then I'll look at my opponent's new ELO rating it's dropped 16 or so points. Or, somewhat similar, I'll lose and go down 8 points, and then my opponent will go up 16 or so points. Why does this happen, especially if we're close to the same ELO?

The site uses the Glicko rating system that includes a measure of rating uncertainty called the rating deviation (RD) value. A player with a higher RD value will see larger rating changes after games. That value drops as more games are played and can increase with gaps in play.

https://support.chess.com/en/articles/8566476-how-do-ratings-work-on-chess-com

I looked this up as I just got 125 rating points from one game???
I played not bad punishing a blunder - but this seems a bit ridiculous

It's your first Blitz game since 2021. The site uses the Glicko rating system which includes a measure of rating uncertainty called the rating deviation (RD) value

When a player has gaps in play their RD value increases and they'll see larger rating changes after games. As you play more, that value will decrease, as well the magnitude of rating changes.