I have replaced my own image decompression with that of Unreal 5. Seemed to be better in my tests. Is it possible that it is only due to SRGB? Please deactivate the checkbox and test again. Could you send me a mesh to test via email? unrealmarketplace@virtualbird.de
Edit
Oh, I just saw in the code that SRGB is now determined automatically. But a test mesh would still be good.