In-Game: [iOS] Slowdown/stuttering seen in my game on iOS 26 devices if built using 2024.14

[hr-oss]

What Is The Bug?

It seems GameMaker games on iOS are being throttled by the system -- my game is not performance-intensive, yet on iOS (but not Android), the app is experiencing framerate drops.

Interestingly, running the debugger/profiler shows the game as putting out 500+ FPS, but on the phone itself, it is visibly choppy.

Additionally, if you observe the game in carousel mode, it runs perfectly smoothly!

I have attached a simple project with a bouncing ball on the bottom and a rectangle you can drag around. You can see intermittently, the ball is changing in speed - even though it should be moving at a constant rate (this is the FPS issues.)

Below is a link to a GameMaker discussion on the matter with additional information: https://forum.gamemaker.io/index.php?threads/getting-slowdown-on-ios26-try-this-one-weird-trick.121354/

Expected Change

This project should be running smoothly

Steps To Reproduce

1. Start GameMaker
2. Run the project on iOS
3. See the issue

How reliably can you recreate this issue using your steps above?

Always

Which version of GameMaker are you reporting this issue for?

2024.14.0 Monthly

Which platform(s) are you seeing the problem on?

iOS

Sample Package

https://api.gamemaker.io/api/github/downloads/ab7d7ca7-0b44-49b1-bbf3-9ae19dd8566b

[jackerley]

Hi @hr-oss sorry for the delay in investigating this, I had to get a new device capable of being upgraded to iOS 26. Now I have such a device I've tried running your project and I'm not seeing any issue, the test runs smoothly on iOS 26 for me. Can I ask what device you are running it on? Does it happen if you are running from Xcode or only from an installed build?

Can you send me what Xcode reports under its Debug Navigator? (The icon that looks like a paint spray can) This is what I am seeing there on an iPhone 16E: (FPS isn't reported as they have deprecated openGL & so have removed it from their tools support, annoyingly)

[hr-oss]

Good day @jackerley, thanks for following up!

This problem was found when using an iPhone 14 (base model.) I have since gotten access to an iPhone 17 also, which does not exhibit the issue. This happens both when running from Xcode, as well as from an installed build.

I'll follow up by Tuesday with that Xcode screenshot for both my iPhone 17 & 14 for you to review!