Perhaps it's a network configuration issue. Have you given all your network devices fixed IP addresses (or equivalent)? Extended their DHCP lease periods?There is definitely something causing interference on the 2.4GHz band but I've had no luck trying to figure it out. I've looked at the spectrum before and it's not overly congested. I've seen much worse congestion where there are less issues. Changing channels did reduce the frequency of the drop outs but it didn't get rid of them. QoS didn't make a difference whether it was enabled or disabled. Microwave could be worth looking into though the issues happen even when it is not being used.
I didn't bother with Harmony support though as the Hub worked fine at my friend's house and it's not the only device havng problems so it's clearly something to do with my network. They are also not that good locally for me. I'm still trying to get to the bottom of it but its just been easier migrating everything off 2.4GHz where I can as that eliminates all issues with minimal effort.