Bug UI Mask is displayed INCORRECTLY with a mobile target

It just uses a round image as a Mask.
When set to iOS Target, a strange pattern appears on the corners.
This did not occur in Unity 2020.3.18 and occurred in Unity 2021.3.16.
Here is the repository that reproduces it.
https://github.com/kyubuns/BugReportUiMask

Does anyone know the cause or workaround for this?

For unity developer
I have already sent a bug report on this issue.
IN-28938

 

It seems to be the same problem as this one.
However, the ScrollRect is not involved, just the Mask.
https://issuetracker.unity3d.com/issues/ios-scrollrect-mask-rendering-issues-when-using-ios

 

I had the same issue with the editor. I managed to solve by changing the mask 'format' in the sprite inspector from 'automatic' to 'RGBA 32 bit.' I haven't checked the built version yet, but I believe that exploring the platform-specific format options might do the trick in that case too.

 

Disabling alpha is transparency in advanced picture settings helped me

 

worked for me, thanks