Blueprint editor Viewport background renders black after switching to forward rendering

Normally the background is grey but in forward rendering it's black.
Doesn't occur for the other viewports e.g. persona

1. Open the editor to a blank project
2. Settings> project settings
3. Click on Rendering
4. Enable Forward Shading
5. Restart the editor
6. Open any blueprint
7. Select the Viewport Tab
   Result
   Background is black, instead of grey