UEFN v40 Issues: Editor Running During Play Session, High GPU Usage, and Stuck Fortnite Window

Summary

Since UEFN / Fortnite v40, the editor no longer pauses during play sessions, causing high GPU usage (100%) as both UEFN and Fortnite run simultaneously. Additionally, Fortnite cannot be closed properly after ending a session, requiring a full PC restart.

Please select what you are reporting on:

Creative

What Type of Bug are you experiencing?

Performance

Steps to Reproduce

  1. Open UEFN and load any project
  2. Move around in the editor viewport (notice stuttering)
  3. Launch a play session
  4. Observe that Fortnite starts normally
  5. While the session is running, check that UEFN is still active and rendering
  6. End the play session
  7. Try to close Fortnite

Expected Result

  • UEFN should pause or reduce activity when a play session starts
  • GPU usage should remain stable (not 100%)
  • Fortnite should close normally after ending the session
  • Editor navigation should remain smooth

Observed Result

  • UEFN continues running and rendering during play sessions
  • GPU usage reaches 100% due to both applications running simultaneously
  • Editor viewport is laggy and stuttering
  • After ending the session, Fortnite remains stuck and cannot be closed
  • The only workaround is to restart the PC after each session

Platform(s)

PC (Windows)