Reduced colour depth after upgrade from Adobe Photoshop Element 2018 to 2026

I'm running Adobe Photoshop Elements on a Win 11 machine which I connect to via Remote Desktop. 

This has worked fine until upgrade to version 2026. See attached images for comparison.

- On my laptop (no remote desktop) version 2026 looks normal
- Element version 2018 - or another applikation - via Remote desktop is normal

- Element version 2026 via Remote desktop: Reduced quality

Thanks for any hints how to overcome this problem