Some backstory:

I grabbed 2 spare units I had lying around and have set it up in my new place. I've got a node downstairs (2 storey home) that's connected to our router via ethernet (cat6) and another node upstairs in the hallway. My study is upstairs so the important node is the one upstairs.

However, the speed is horrendous.

The speed from the provider is meant to be 200mbps. Ran a few speed tests and router shows 200mbps, while main deco node gives me 190-200mbps downstairs. The node upstairs however is giving me 40-80mbps.

I've turned off WiFi connectivity for my router (just saw this as a potential fix on Google). I'm completely clueless when it comes to mesh systems so any help is appreciated.

A couple of questions:

1. Is this mainly due to an outdated model and would purchasing newer models solve this issue?

2. The way this house is structured (note: rental so I can't redo electrical wires for more sockets etc.) - the connection point for router is downstairs and the staircase is enclosed (walls on each side). Node upstairs is pretty close to the staircase and I'd say is about 15-20m from the main node. Signal I get upstairs is "Medium". Is there any way to improve this other than placing the 2nd node elsewhere? As I'm limited with power points and can't install ethernet cables that require drilling from the outside (definitely do not prefer having a cable running through the entire inside of my house)

Thanks!