Lag on macOS Sonoma

[turtle_hat]

Issue

Hi! Big Celeste fan here. I've been playing through Farewell a lot recently to train up for the golden berry, but a couple days ago my MacBook automatically updated to macOS Sonoma without me telling it to. Things have been mostly fine, but for some reason Celeste will now often slow down in the middle of a play session, dropping down to half the usual framerate or lower. I haven't been able to find a consistent pattern to when or why it does this, but I suspect large screens (of which Farewell has a lot!) set it off more easily. I just did a full run of Farewell where it happened on 6 screens throughout the level.

(Temporary) Fix

I've found one way to solve the problem whenever it pops up, but it's not exactly ideal. If I pause and go into the game's video settings, toggle the Fullscreen setting, then unpause, the game will be back at its usual crisp framerate. However, the slowness can return at any time after doing this, and it takes a few seconds to pause and go into the menu, which for a speed- and focus-heavy game like Celeste can be pretty frustrating. I haven't found any other ways around it yet.

Computer Specs

My computer is a 15-inch 2018 MacBook Pro with the following specs:

• macOS: Sonoma 14.2.1
  
• Processor: 2.9 GHz 6-Core Intel Core i9
  
• Graphics: Intel UHD Graphics 630 1536 MB
  
• Memory: 32 GB 2400 MHz DDR4

If anyone finds a way around this, please let me know, and if by chance EXOK sees this, I would be very grateful for an update to fix the issue. I'll also be happy to offer more info if it would help you troubleshoot. Thanks!

[Perseus]

Have you tried verifying the integrity of game files? (Library -> Right-click on game -> Properties -> Installed Files -> Verify integrity of game files)
Have you tried switching to the OpenGL beta branch? (Library -> Right-click on game -> Properties -> Betas)

[turtle_hat]

Just tried both of these, the files were all verified and the issue still occurred in the OpenGL beta (if I installed it correctly, which I think I did). Appreciate the suggestions though.

I did find out that if I just kept playing with the lag instead of toggling the fullscreen mode to fix it, it does seem to go away after a few screens, though like with using the fix, it can return later on.

I'm wondering if it might be caused by my computer or the game running out of memory? I'll try playing with Activity Monitor open sometime soon to see if that reveals anything.