Since a few days the interface is very slow while rendering play actions and while doing so, my CPU load goes to 100% (I noticed first because the laptop fan started kicking in). It seems to be due to the graphics rendering, since it's noticeable during the AI opponent's turn and auto-playing multiple cards especially. Actions that render cards (e.g. when playing Rabble) don't appear smoothly at all.
This is on Debian Linux (stable/Trixie) with Firefox 153.4.0esr.
Now it's working smoothly again without high CPU load. Not sure if anything changed server side. I'm fairly sure nothing changed on my side, not even restarting the browser.
Some problem was a day or two ago identified reagarding pre-moves. I'm not sure if it fixed or if it even is your problem. If it comes back, post again here.
It's back again, not sure it was ever fully away. Games run smoothly for the first 1-2 turns, but then quickly deteriorate. Setting animation speed to none doesn't help.
I noticed that I got a security update for Firefox, so maybe that affected things (as it seems to be client-side rendering problems), but I think the timing wasn't exactly matching.
I tried also in Chromium. There the issue doesn't appear. When I exited the browser halfway in game #184311193 and continued it in Firefox, initially a couple of card plays it was smooth, but then started deteriorating again.