Just started tonight, where my frame rate for things is noticeably slower.
For speed moving it feels like its 10-15% slower..... but for OTHER parts, its ridiculously slower.
When it shows our scores in comp, it lags so much the final total damage comes up faster than the individual scores due to those scrolling through all the numbers to get to the score. Also lags on random things like I had a game where I finished, said GG to my opponent, went and got another game almost immediately, and about 2 seconds into my new game the "player name has left chat" message popped up from the previous game.
There is a post on Reddit from a user saying they have been having this problem since yesterday. As I said, mine just started tonight. https://www.reddit.com/r/geoguessr/comments/1rqo120/anyone_else_getting_horrible_frameslag_in_duels/