Triple screen - strange white residue on left screen

Hi, has anyone ever seen this before? Hard to describe so I’ve attached pictures. All my screens are setup exactly the same in Windows and are same make and model. Using HDR and same colour profile in Windows across all and same refresh rate. This only happens in MSFS2024 - no other game/application or normal windows desktop activity. In the last two pics, the screen on the left has the strange artefacts and the one on the right is normal. Any ideas?!

Try with HDR off ?

Good point, will give that a go.