Two bugs, both related to the Environment Lighting setup.
When a new file is created with EEVEE/Cycles as the default engine and an Environment Texture with a HDRi image is setup.
Or an older Blender 2.8 file setup with a previous RPR for 2.80 is opened.
Nether scenario preserves the Environment settings (they should be setup in the IBL section).
This also includes the intensity setting which is not preserved from either of the above beginnings.
I actually don't quite understand what the issue is here. Are you saying that old files have change environment settings? (They have. we are still in Beta).
Okay, forget the older RPR files bit. We're used to older RPR stuff needing to be recreated.
If you setup a brand new Blender file in EEVEE or Cycles with the environment settings you required...... then later set the Render Engine to RPR the settings are completely lost. Whereas in RPR v2.0.52 they were preserved correctly. It is a regression.