Bug WebGL builds broken for iPhone 12 iOS 16

WebGL builds for multiple Unity versions seem to be broken for iPhone 12 on iOS 16 (app just hangs). Interestingly the build works just fine on later iPhones so seems like a device specific issue. I've tested both on my own iPhone 12 and through Browserstack.

I've been using https://github.com/JohannesDeml/UnityWebGL-LoadingTest to test, basically none of the builds work on iPhone 12 but seem to work fine on later iPhones. I was able to resolve by disabling the "WebGL via Metal" feature so definitely appears to be a iPhone/Safari issue. Any idea what the problem could be? To replicate try running https://deml.io/experiments/unity-webgl/2022.2.2f1-webgl2/ on an iPhone 12 device. Thanks!

[Edit: Looks like it's working on iPhone 13 and up]