New Problem in Blender 2.8 since last few builds and AMD Vega GPU problem

I’m currently using 2.8 that I downloaded on around 4th March, which is working fine for me. Few days ago (on 17th & 18th) I downloaded two latest versions of those dates. But when I opened my main project file in them, not just my render but even my matcap is showing as messed up in eevee.

I carefully matched the render settings (and all subsettings inside them, and their values), but they are same. Nor was the light moved. nothing was changed.

Here are the screenshots:
Working on March 4th Build:

Not working on 18th March Build (I deleted the 17th March Build, but it was same)

The normal cube is working fine in 18th March build:

Also I have a second issue, regarding my GPU not being used. I have replied here:

I ran clinfo, and my file seems fine. Ofcourse I have the latest AMD GPU Asus RX Vega 64, so it does have OpenCL imho. I have used multiple versions of 2.8 since January, but have not seen my GPU getting stressed so far.

For example, I unchecked the second listing of my GPU, and checked the CPU (which I assume makes the GPU and CPU work together). My render time for a sample scene went from 8 minutes to 1 minutes, but during the rendering, I didn’t see my GPU utilization going above 7% in task manager, while my CPU went above 83% or so.

I also have a Nvme SSD, so that shouldn’t be a bottleneck either.

This is not an end-user support forum, if it’s a bug, it can be reported in the tracker, general discussion about hardware and issues can take place at