Well, given how close you are trying to work to the hub, is there any way you could do some tests using an ethernet cable, rather than wireless? See if the issue exists when you're directly cabled into the hub..
Separately, it's worth setting up a BQM and sharing the "live link" back here
it's also worth posting the output from the upstream, downstream and network log tabs on your router.. to get these, browse to http://192.168.0.1 - don't log in, instead click "router status" where you'll find all of that information - you will need to break this down over multiple posts as it's too much data for a single post..