Hi Mario. Did you find a solution? We ran into a similar problem recently and seems like TestFlight is doing something that is breaking “semi transparent” pixels in the image. I can see this also in your image, you pixels with full colour are fine but those pixels close to the borders of your button where there are semi transparency is not rendered correctly.
Would be interested to know if you published and if you had the same issue in App Store as in TestFlight?
Hoping to find a solution that does not involve reloading all our images
EricApple
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