Mibox kills wireless

I’m running Kodi on a MIBox with a plug in, and it works just fine.
BUT after about 15 minutes into a film, the wi-fi stops working, and I have to reset the router. No device will connect to the wireless then until a router reboot.

The same router/wireless works perfectly day to day for Netflix app on the TV.

Any clue what might be happening with Kodi/Mibox?