[RESOLVED] FPS drops / spikes / stuttering every now and then (UDP transport and VPN)

Hi there!

I just downloaded UE 5 and experience heavy FPS drop spikes every few seconds.
I am not able to narrow this down any further. It’s not related to the level that is open and happens both inside the editor and while playing in PIE. It even happens in a pitch black blank level that I created freshly.

While the fps are generally stable at 100-120, every 3 to 4 seconds they just spike down to 80 or less with a very disruptive stutter.

Does anyone experience this too or have a solution / lead to a solution?

Thanks in advance!

Curiously, this is actually related to network settings. If you have the same problem and disable UDP transport in the project settings, the stutters should disappear.
If you do not want to tamper with default network settings, disabling the LogMeIn Hamachi network adapter in Windows instead worked for me. Other VPN software might behave similarly.

Does anyone know how this can affect framerate so badly?


I randomly tried out an old 4.27 project and the problem occurs there too.
Reinstalled the graphics card driver (was already up to date) and checked that there are no pending Windows updates.

I checked the performance through the task manager, nothing noticable there either.

I just logged in to say THANK YOU, it was the network transport and i have no idea why, how bizarre


OMG this was driving me crazy!!! For me the disabling UDP network transport fixed it. Thank you, you saved me from pulling my hair!!