System Information
Operating system: Windows-10-10.0.17763 64 Bits
Graphics card: AMD Radeon HD 7600M Series ATI Technologies Inc. 4.5.13422 Core Profile Context 0

Blender Version
Broken: version: 2.81 (sub 12), branch: master, commit date: 2019-09-24 17:25, hash: rB3142ae19d227
Worked: (optional)

Short description of error
eevee camera "offscreen" black background bug

when zoomm the quadrant of the camera beyond the visible area, in eevee render mode, in the switch between fullscreen and normal window, the background turns black for a few moments. it only happens in this circumstance.

P.S. the wanderer scene has a background that has been constructed in a procedural way, probably due to some node.

see the video .