Colours change between the Develop and Library Modules

[KDWalter1]

Before anyone replies, I know about the problem of GPU acceleration on some cards. 

This is a brand new iMac with AMD Radeon Pro 5700 XT 16 GB

The problem is there with acceleration switched on or not and the only colour profile assigned at the moment is that which came with the Mac

Library module shows a picture with far less saturation, especially in the oranges

Any clues anyone?

[DdeGannes]

As you indicate in your post there are issues with macOS (which have been acknowledged by Adobe) and LrC 10 the bulk of which are most evident to versions 10.1 and 10.1.1, it is better to revert to 10.0 until the fix Adobe is working on is released.