Post processing effect not working in android es2 feature level

I have applied a post process volume which is set to unbound It works well in the normal preview level but when I switch to the Android preview level, it doesn’t work.

What could be the cause?

Are You talking about custom PP shader or basic functions? Since ES2 is quite limited.

I have another project in 4.15 that the postprocess works fine in. at the same es2 feature level