4.21 IOS Platform Render Has Mosaic?

 After the project was upgraded from 4.20.1 to 4.21 there was Mosaic in some Materials of iOS  Platform ,Just like this! 
It only happens on Mac and iOS, but it  works on Windows.  Up is on Mac ,Down is On Windows.
How can I fix that on Mac and iOS, this is an App which will run on iOS  platform. 

Did you fix this?
I have the same problem.T^T