Render Target Material is clipped as an Image within UMG when attempting to set to fullscreen while playing in Standalone mode.
The interesting thing I noticed about this bug is that the issue is not apparent when using the command console 'r.setRes ResolutionxResolutionf' versus simply pressing the 'Alt+Enter' key.
A simple workaround I suggested was to use the console command instead of the shortcut key. I have added some example images to preview the issue.
1. Download UMGSceneCapture.zip project attached.
2. Launch the Uproject File.
3. Play in Standalone mode.
4. Use Alt+Enter to enter Fullscreen Mode
5. Observe how the Render Target Image is Clipped/
6. Exit and replay in Standalone again but use 'r.SetRes 1920x1080f' console command.
7. Observe how it is goes fullscreen correctly and the UMG Image is not clipped.
Expected: Alt+Enter works the same as the console command when setting fullscreen mode.
Outcome: Alt+Enter clips the UMG Image
Head over to the existing Questions & Answers thread and let us know what's up.