Two Playstation over a Fritzbox?

Sh
- in PlayStation
4

My Fritzbox is on the first floor and my room is one floor above. I use a Lan Repeater (Fritz Box Powerline 510) for my Playstation. Now my cousin is staying with me and he has brought his Playstation with him. I also have a Wi-Fi repeater and I thought it could easily play over it and I can play on my usual Lan repeater. However, it is extremely lagging. Then I tried to connect both via LAN, with a LAN adapter that has two connections. One Playstation had internet access and the other didn't. In the end I pulled a 20 meter cable all the way down and connected it directly to the box. Both Ps had internet and, according to the internet test, even very good. Nevertheless, the game was very stiff for both of us, so it is unplayable.

Is there any way you can help me out what I can do as no internet expert to have better internet?

Cu

Nevertheless, the game was very stiff for both of us, so it is unplayable.

This is because you share an internet line.

Sh

Yes, I think so, but is it impossible without laggs or how can I understand it?

Cu

You have to buy a better internet contract.

Li

You have caused a network malfunction. It's pretty wired, I know that