I have a 4G phone which in the corner of my house receives 4G signal, and using speediest.net I get about 20Mbps, if I'm connected directly to my phone from my laptop and sitting next to it.
My bedroom is on the opposite side of the house and in it my phone doesn't receive 4G. So I bought a WiFi extender, with the hopes of leaving my phone in the corner that gets 4G and using my laptop in my bedroom.
If I sit next to my phone and connect to the extender (which is extending my phone's hotspot), then i get about 7Mbps. However if I sit in my room and connect to the WiFi extender I get 0.9Mbps. If I run the speediest on my phone I get 20Mbps still.
Why does the distance between my laptop and WiFi extender affect the speed of the internet? Meanwhile if I transfer stuff to my phone or VNC to it (i.e. local connections) whether I am in my bedroom or next to my phone and connected via the extender.