Changes made to the Preview Scene Settings in the Material Editor are not saved. The preview scene will default to grey background instead of EpicQuadPanorama_CC+EV1 because "Show Environment" is always unchecked when material editor opens. Verified that this occurs in 4.19.0 but NOT in 4.18.3.
Result: Preview Settings are not saved. "Show Environment" is always disabled.
Expected: Preview Settings are saved.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-55762 in the post.