Packaged Build Different to PIE in UE 5.1.0 where it was identical in UE 5.0.3, WHY?

What could cause differences between HUD displays hosting Capture2d pixels to behave differently in the Play in Editor compared with a Packaged Build, in UE 5.1.0 where it was identical in UE 5.0.3 on Linux
We have found that some we lost functionality between 5.0.3 and 5.1.0 on Linux

But we need 5.1.0 for Lumen and Raytraced support within a Capture2d render to a HUD display

Can we work with your developers to find the cause of this issue.