I recently upgraded a 4.18.3 project to 4.19.1, and the Move & Scale widgets are not rendering correctly in the editor in Lit & Unlit modes.
You can see the widget rendering on top of the light icon here.
Widget is fine if you switch to Wireframe mode:
Rotate widget edges appear, but the center does not:
Project settings:
- this is a VR project, with target platform set to Mobile and 3d/2d Scalable, but is not a mobile project
- Uses Forward Rendering and Instanced Stereo.
Steps taken based on older questions with this problem (The Move and Scale Gizmos do not render - Community & Industry Discussion - Epic Developer Community Forums):
- I’m not in Game mode
- mobile preview is not on (preview set to Shader Model 5)
- mobile HDR is off
- Show Transform Widget is On
- Deleting the Saved and Intermediate folders doesn’t fix the problem
- I’ve reset all of the settings I can think of
- I’ve deleted the project’s DerivedDataCache and the one for 4.18 and 4.19 in app data / user to force rebuild shaders
This issue occurs in all project maps, even blank maps with no lighting objects, and it occurs on two different machines connected to the project via source control.
I can manipulate objects by going into wireframe mode, but having to switch between Lit and Wireframe constantly is making me pull my hair out 
Update: I rolled my project back to 4.18.3 and the widget appears normally. If I update the project again (via a copy) to 4.19.1 the widgets break again.
Update 2: If I start a blank 4.18.3 project with the same basic settings as mine and convert to 4.19.1 it’s fine. No clue what is broken in my project.