When updating to iOS 18.2 or later, there are devices where the scene becomes dark.

[maiku]

Please see:

Can We Generate 2048px resolutions lightmaps?

Hi! We have released a workaround which does not cause lack of reflections and fixes the WebGL crash for Apple devices which were experiencing it. No suffix in the URL is needed, but your device may require a restart. We have verified it fixes the issue on iPhone XR and iPad 8th generation - both of them were experiencing this crash. Most Apple devices were not affected by this iOS bug, but all the remaining devices (older iPhones and iPads with iOS 18.2+) should be working now without any issue…