Question unity webgl visual glitch on iphone with opacity background on web

This screenshot is a part of the webgl game which from the mobile view.
the ui looks correct, but the 3d mesh looks broken.

still not test enough, but currently, this phenomenon not happens on andriod phone
only happend on my friend's phone which IPhone 11 pro

I think this maybe caused by PostProcessing?
Meanwhile, we also use a method to set the background opacity to show the mesh above web page which from these articles:

https://support.unity.com/hc/en-us/...048.597631836.1586496094-324193956.1586496094

https://forum.unity.com/threads/web...05.524976980.1586484471-1016004096.1586484471

I guess maybe have some relate with this?
These article also old enough, maybe the method need some new adjust in these newly version?

Is there someone familier with this glitch? Hope could get some idea and clue for fix this.
by the way,

Much appreciate!

 

iOS only supports WebGL 1.0 for now. Until 2.0 is supported or you are explicitly developing for 1.0, my advice is to wait.

Also, WebGL is not officially supported on mobile by Unity (yet).

 

Thank you so much for your sharing!