Best answer by Stanley_4
Is the Boost on the same network?
Any smart switches in the setup that could be messing the Sonos STP setup stuff?
Doing client isolation on your WiFi?
Are the 2.4 and 5 GHz radios on the same network?
Are the WiFi credentials removed from the Sonos setup?
Maybe turn off Airtime Fairness but I don't think so.
Worst case get it to act up, submit a diagnostic and contact Sonos (twitter and facebook are staffed 24x7) or post the number here and sometime Monday Sonos should see it.