NPC Spawn Lag and Skin Loading Issues Over Time

Summary

In our UEFN game “Time Travel [Roguelike]”, some players experience severe lag during NPC spawns after playing for a while. The issue becomes more frequent on lower-end PCs and is characterized by the NPC’s weapon appearing first, followed by either a delayed appearance of the NPC or a default Fortnite skin replacing the intended one. This bug worsens over time and only resets when rejoining the server. It negatively impacts players experience.

Please select what you are reporting on:

Unreal Editor for Fortnite

What Type of Bug are you experiencing?

Character

Steps to Reproduce

  1. Use a mid-range PC and set Fortnite graphic settings to maximum.
  2. Create a empty island with 16 NPCs spawners.
  3. Spawn NPCs every 20 sec and kill them (with a Damage Zone) 10s after their spawn
  4. Continue playing for a few minutes
  5. Observe the behavior of NPC spawns lags

Expected Result

NPCs should spawn instantly with their correct skins and no visual or performance delay, regardless of playtime or system performance.

Observed Result

After some time:

  • Only the weapon appears first.
  • Either the NPC spawns later, or a default Fortnite character skin appears instead.
  • The issue gets progressively worse and does not resolve unless the player leaves and rejoins the server.

Platform(s)

PC & Console

Island Code

9798-3463-3051

Video

Additional Notes

  • The issue is more frequent on lower-performance PCs or when GPU load is high.
  • It can also occur on high-end machines after extended sessions (1h+).
  • Bug severity correlates with:
    • Length of the play session
    • GPU performance/load
    • Background apps using GPU
    • Number and frequency of NPC spawns
    • Time of day (more frequent during evening CET) when a lot of people play Fortnite
  • We can consistently reproduce the issue using a test case with elevated graphic settings and sustained NPC spawning.
  • Video evidence attached.

FORT-899641 has been created and its status is ‘Unconfirmed’. This is now in a queue to be reproduced and confirmed.