Try turning off the 5GHz wireless on the home hub, and see if everything stays connected to 2.4GHz.
I can't choose the channel anywhere when they're not split or split.
Like I said, changing the channels made no difference.
if you go to hub manager then advanced settings then wireless then it will show current channel for both 2.4/5ghz by selecting the channel it will open and show you the choices 1, 6, 11 and smart or 36, 40, 44, 48 and smart
as you have the hh6 you can also split the networks which normally helps with wifi connections as many devices do not like the bands combined
you can also try changing the wireless mode from default 1 to either 2 or 3
my bands are not separated and I can select the channel for either or both band
separated band from many posts are preferable as many devices have problems when 2.4/5ghz are combined
still your choice as you are the person with the problem