is it just wireless connections that are dropping out, or are you also seeing wired connections drop at the same time?
it's worth setting up a BQM to see how the connection looks from the outside.
Post the information from the Upstream, Downstream and Network Log tabs on your hub too - to do this, browse to http://192.168.0.1 but don't log in - click, on Router Status - you'll see those tabs there.. copy the tables from each one back here - one tab per post.
can you post the live link for your BQM? if you select the live view, and then underneath there will be a "create sharing link" or similar that will generate the image but remove your IP address so that it's safe to post here..
also still need the upstream/downstream/network log tabs from your hub.
downstream power levels are all below what i understand to be the "minimum" and you're getting a lot of RCS Partial Timeouts in the log.. believe you'll need an engineer to sort this..
interestingly, in spite of the low power levels and RCS events, your BQM doesn't look terrible (though you can see the packet loss creeping in at the top).
best option, i reckon, is waiting around here for a forum staffer to pick this up and comment (hopefully some of the other community members that know more about the powerlevels/timeout issues will also comment too :))