As of today we have a new Wi-Fi connection with 250k. On my father's laptop you can see exactly what, who gets how much I get for example 70Mb / s is actually nice and good. But on the PC I only get 2 Mb / s in tests what could be the reason. The LAN connection is usually very good only since the change. In addition, a light flashes on the LAN plug that brings the Internet to my PC (so it is right next to it). Otherwise this only flashes when I have bad internet.
Call your provider's hotline, they can help.