It's just a massive drop when trying to access the wi-fi out the back of the house (2 brick walls between the location)
That's exactly what I would expect 2 brick walls to do to a WiFi signal.
My laptop does not support the 5ghz speed so maybe there lies the problem, 2.4ghz network only.
5GHz is best for high speeds at short distance.
2.4GHz is best for longer range or going through walls (lower frequencies penetrate better).
The 2.4ghz wi-fi is set to channel 6 and the 5ghz wi-fi channel 36. Not sure of these can be changed?
You can use an Android app like WiFi Analyser to see what channels your neighbours are on.
No idea if the Smart Hub 2 allows you to change channel. Mines is still sealed in its box.
The Hubs are usually good at picking the best channel automatically.