Abysmal PIE performance with multiple clients open

I am running the 5.3.2 release, built from source, but same thing happens with the prebuilt binaries.

I made a new game project with the third person template, scalable settings, raytracing off. stat fps displays ~60FPS, which is expected.
However, if I set the Number of Players to 2 and the Net Mode to Play As Client, it drops down to a pretty consistent ~37FPS.
3 players: ~24.66FPS.
4 players: ~18.5FPS.

Considering the frame rate is fairly stable, I reckon that Unreal is limiting my performance somehow or is being bottlenecked by something. I am certain that my PC (RTX 4090, 13700K Intel CPU) can handle a load like this.

I was wondering if anyone have any ideas on what could cause this, or potential fixes.

I would also like to point out that I experience similar issues by having a blueprint window open on my second monitor (absymal performance) however that is a separate and totally workable issue. Poor multiplayer performance is not. I’m simply pointing it out because it seems like it could be related.

Let me know if there are any details I could provide that could make the issue clearer. Thank you!!

EDIT: My video drivers are fully updated. Playing in Standalone Game (not PIE) allows all instances to run at 60FPS, but working with PIE would be a huge help.