We have a 5G internet connection at home with an antenna on the outer wall. The WiFi speed downstairs is good, up to 370 Mbps. Despite having a mesh extender upstairs, the internet is slow there, only 10 Mbps. I don't want to drill holes in the ceiling for Ethernet cabling, so I bought a TP-Link AV1000 Powerline starter kit. The device's software indicates a good speed of 190 Mbps through the power network, and for example, YouTube videos play smoothly and without interruptions. However, games won't load, and many plugin-type videos on various websites won't open. I have updated the TP-Link device and have also tried turning off the firewall and antivirus, but some websites and games selectively don't work, even though the speed appears to be good. Could someone advise what might be causing this issue?