Whilst it may not be convenient, are you able to test the connection using a device directly connected to the hub via ethernet, rather than wifi? Do the dropouts happen at the same time when connected via cable?
it would be worth setting up a BQM - once set up, find the Live Graph and click "Create Sharing Link" - post that back here.
Next, browse to your hub on http://192.168.0.1 - don't log in, click Router Status - copy/paste the tables from the Upstream, Downstream and Network Log tabs back to this thread - you'll need multiple posts for this, the info wont all fit into a single one..