I still live with my brother (with my parents). But the problem is that he uses the entire Wi-Fi. He plays on his Ps4 multiplayer, which is amplified with a Wi-Fi amplifier, talks to people in parties (just like calls on ps4 with several people), and according to fritz.box, his cell phone also pulls extreme amounts of Wi-Fi, even more than anything else in the whole house. For me everything stutters all day (cell phone, laptop).
Can I do something else?
Yes, you can talk about it.
I've already tried it, it doesn't work for him.
For that there are QoS settings on the router. Or you can go online via Ethernet from now on.
Then talk to your parents or talk to everyone about it.
Go to the config menu of the router, activate the MAC address filter and enter YOUR MAC there… It is outside - with all devices… 😁😁