We have been having the same problem my son has an Xbox one, in the next room to the hub, it continually drops the signal, I bought a booster box for the wifi, which helped for a while, but the problem keeps happening I have to reboot the hub for him.
Sorry you are having problems with the Xbox dropping connections, we are aware of a problem with the Superhub2AC that may cause it however you are using a Superhub2. Perhaps it is a wireless issue, we have some wireless guides that may help although if possible we would always recommend a wired connection for gaming.
Also I notice that the signal level received at the hub is a little low:-
No problem. The hub is a Superhub2AC and currently has the suspect firmware on it, please accept our apologies, we are currently investigating please keep an eye on the forum for updates. Also we have a problem in your area with intermittent low SNR. This may cause packet loss and lag. Our engineers are trying to find it F004974171 estimated fix 20 JAN 2017 20:00. I have updated your account so if we have your mobile hopefully you may get SMS updates.