Question NETGEAR, my internet is being throttled by my brother

[MilkWookie]

So I have my NETGEAR internet that we’ve had for years and we live pretty far out from cities so our internet isn’t the greatest already, my internet on my computer used to be downloading games on steam at like 800kb/S but not it has gotten to like 500 ish overtime but I think that’s because of my brother, on our internet when I go to my device on NETGEAR it says signal strength -56% and I’m not sure how that happened or how to fix it but I’m wondering if any of you have had the same experience, and also he has a wifi extender because he lives the farthest away from the router in the house and I am 1 room away from it.
Speed test: https://ibb.co/ftrsD2r
Signal strength :https://ibb.co/wNxcQFT

 

[Ralston18]

Distance is only one factor. What is between the wireless router and your computer also matters. Both physically and electronically (sources of interference).

Configuration matters. What frequency and channel are you using? What wireless adapter are you using, how old, current drivers, configuration settings?

One room away: any chance that you can use a wired connection or perhaps powerline adapters?

However, the heart of the issue is family.

Who has full admin rights to the family/network router?

Everyone needs to get together and work together to share.

Likely not a technical issue per se.

Time for a family meeting.