Asset Flickering when Viewed on some iOS Devices

I have a 2D Unity WebGL app that is usually run on desktop devices, but is sometimes accessed via iPad. We have started observing that when viewing the app on certain iPads there is severe graphics flickering. We have not identified a pattern with what iPads experience this (it doesn't seem to be performance related).

I've experimented with different things. The issue seems to be unrelated to framerate (lower framerates just reduce the speed of the flickering). I've also disabled lightmap streaming and forced WebGL 1.0 as the only graphics API, but neither of those had any noticeable impact.

Are there any other settings I could try playing with that might make a difference?

 

Did you try setting shader precision model in the ProjectSettings/Player/Other Settings section to "Use full sampler precision by default"?

 

@xavier-ateo Thank you for your reply. I should have mentioned in my description, I am using Unity 2019.4. I'm not seeing the option you mentioned in my player settings. I think that must have been added later.

 

No worries. I'm only guessing that it might have to do with shader precision.
Especially with thin objects fare away from the camera, flickering can occur when using a lower precision mode for your shaders.

You can read up on it here:
https://docs.unity3d.com/2019.4/Documentation/Manual/SL-DataTypesAndPrecision.html

My assumtion is that your iPad's GPU might not support higher precision floats on WebGL... (But I'm really not an expert on any of this.)