when you're near the hub does everything work ok? Have you done any testing with a device that is directly cabled into the hub?
Just want to make sure that it's just wifi range/signal that's a problem, and not anything with the underlying connection.. if it is just wifi then you have a couple of options..
1. refine the wifi broadcasts from the hub and hope that it improves things
2. buy a new, better, router or mesh system and use the hub in modem mode..
for option 1: log into http://192.168.0.1 and navigate to advanced -> wireless -> smart wifi - tick the box to disable channel optimisation and save. then navigate to advanced -> wireless and rename the two networks in there - you could just append _2 and _5 - click apply and restart the hub.. you will now see two wifi networks - connect devices to these networks.
5ghz is usually a lot faster but has a shorter range, so if your device shows that as an option, use it, but be mindful of range..