When I play on the Xbox Rocket League, I have a stable ping of around 50, on my PC again in the same WLAN I don't get below 200. What can be the reason? Are the servers on the PC worse? Is the WLAN not arriving correctly on my PC?
Wi-Fi on pc? Either you have a lan cable or a wlan usb adapter and I think the second one with the ping is more likely
Turn down the graphics settings, then it should run smoother!