you can type resmon into the "run" box you see when you press the windows key. The application is called resource monitor and you can find it someplace in the windows tools menu if you want to find it that way.
When you have any kind of wireless in the path you run the risk of interference that causes packet loss and latency spikes. Games unlike almost all other traffic does not tolerate packet loss or latency issues. Everything else can use buffers to hide these issues.
It will likely prove what you already know but it is the standard tests.
Start with tracert 8.8.8.8
This will show nothing likely ,the goal is to get the ip of the router in the path.
Now open multiple cmd windows and run ping to hop 1, hop 2 and 8.8.8.8. You will likely see no loss to hop 1 which is your router. And loss to hop 2 and 8.8.8.8. Hop 2 for most people represents the connection between your house and the isp for most people. If you see nothing here you can try hop 3. Hopefully the ISP has not disabled the ability of the router to respond to ping....again because of denial of service.
For a person that has fiber or cable to their house they can call the ISP and they wil fix it. When you have wireless of any kind including cellular mobile broadband it is extremely common to get loss and they can't really fix it.