Graphic settings break network game


I have some serious issues with UE 4.17 and my multiplayer game. Lower graphic settings break the game entirely or cause massive lags for the client.

Player who host the server runns on lowest settings: game is completly broken. Joining the session and loading the map works, no HUD gets created nor the player gets spawned.

Server high/epic | Client low: Server runs fine, client can join and move, however the client model stays at it’s spawn location while the client is able to fly as a ghost araound ad shoot/kill other clients.

Server high/epic | Client medium: Server runs fine, client can join and move and play, however has serius lag issues.

Server high/epic | Client high/epic: games runes fine for everyone and is perfectly playable.

I already removed my entire settings menu and replaced it with only consol commands and tested everything wil clean installations → same result.

We where able to reproduce this on multiply clients with diverent servers. I don’t know how and why but for some reasons graphic settings are connected to network related stuff and can break the entire game.
I’m using UE 4.17 with Advanced Session Plugin.

Did anyone else ever had a problem like this or even knows how to solve it?
I’m extremly frustrated, testing and debugging for hours now and don’t get the connection between graphical settings and network.

Still having serious issues.