System Information
Operating system: Windows-10-10.0.19041-SP0 64 Bits
Graphics card: AMD Radeon RX 5700 ATI Technologies Inc. 4.5.14736 Core Profile Context 20.8.2 27.20.2001.16003

Blender Version
Broken: version: 2.91.0 Alpha, branch: master, commit date: 2020-08-25 19:28, hash: rB396d39c6b904
Worked: (newest version of Blender that worked as expected)

Short description of error
when trying to add a frame node the background of the shader/composting workspace turns grey
but the frame node does not show up.

Exact steps for others to reproduce the error
open a new blender (alpha) session then go to shader/composting workspace and add a frame node.

tested in beta build and it works fine

[Based on the default startup or an attached .blend file (as simple as possible)]