FYI There was an updated version of macOS 26 released for the public, the build is one higher than the RC. (25A354 is the newest, 25A353 is the RC). So I just updated a little bit ago, and will be checking it during keys later tonight.
It definitely happens more likely (for me) when in raid or in M+. This is such a weird bug.
P.S. I AM getting it in MoP Classic, I just hadn’t been in a raid until today, and the scroll-lag is fragmenting frame rates there as well as Retail.
Yeah I grabbed the 1 newer build as well, but won’t raid again until tomorrow to retest.
Just chiming in to acknowledge this exact issue (in Tahoe now as well) on an M1 Max.
The newer build hasn’t improved anything from what I can see - I would assume such a slight increase in the build is probably just disabling the test status of the release.
they disable that in RC, sometimes public going live is same build. from what I saw iOS didn’t get new build for release, but watchOS and macOS did.
I noticed that too, lol.
Not 100% the same issue but related I believe. These issues are happening in WoW Classic Hardcore Anniversary (Although I assume it’s the same for all classic). Recently updated to MacOS 26 today and the game seems to be stuttering when moving without using auto run. It doesn’t happen when you first open the game like OP said but the longer you play the worse it gets. What I’m finding weird though is that my FPS stays at 60 (monitor refresh rate) the whole time, even when the stuttering is occurring (If you use auto run it immediately goes back to smooth again). I’ve also noticed this stutter happens when holding the right mouse button to look around. It isn’t related to the old micro stutter that (used to) happen(s) when releasing a mouse button without a mic attached and being used by the Mac
Have also noticed new “border” in borderless
M4 Mac mini Base model
(Sorry if explanation is poor, happy to clarify anything)
This might not help anyone else, but I was having a lot of frame drops from a steady 60 frames a second in classic anniversary to down in the 20s when I would engage a mob. It was very obvious that there was a lot of stuttering during combat. I tried a few different things and I turned off vertical sync in WoW and I haven’t had the frame rate drop since then. It’s staying around 60 or so. There is the occasional drop into the 50s and maybe upper 40s, but for the most part it staying pretty close to 60 frames.
I am on an M2 Mac Studio Ultra. I did update to Tahoe yesterday when the release came out and the first time I noticed any issues was after Tahoe.
I’m also having this same behavior on my M3 Max machine, hopefully this gets fixed quickly. I’m used to having 120fps and no fan noise, but I’m getting lots of frame rate drops and the fan will keep getting louder the longer I run the game.
I don’t play retail, just MoP classic.
Also experiencing this on tahoe release. I mostly idle in Dorn and hop into arenas. Maybe after 4-6 matches it starts stuttering.
Edit: OP - are you using Game Mode?
Blizzard has identified cause and a potential workaround for time being. It is looking to indeed be an apple bug and not just one that affects WoW but ANY application open for extended period of time in macOS
here is work around:
Open terminal and run this command to disable autofill heuristic controller
defaults write -g NSAutoFillHeuristicControllerEnabled -bool FALSE
this function appears to be repeatedly registering input responders over and over
Been testing work around. seems promising
This seems like it did the trick for me.
One command was all it took to keep me from needing to go back to old MacOS, TYSM Brothers!
Great thanks! Should we also report it to Apple or will Blizzard do that directly?
Any news regarding the new “border”?
blizzard is gonna report it to apple directly. it’s a pretty serious issue. it affects all apps. for example https://github.com/ghostty-org/ghostty/discussions/8616
it even affects safari and finder over time too. you’re gonna notice tahoe feels way better when you turn this off
it does appear apps have ability to turn it off per application basis. blizz is exploring that.
Workaround seems to be working for me which is great, thanks!
Does this command survive reboots?
yes it does.
This has solved the performance drop for me. I played for 4-5 hours this evening with no degredation.