I'm operating on a Samsung tablet with Hotspot that I get through USCellular. The internet regularly cuts out when the tablet still shows I have a normal strength signal. I tried googling the problem and while a lot of it might as well have been in Chinese, it did say it might be the router.
So what's a router? Is it inside my tablet? Or is their server getting jammed up with a lot of traffic (it happens during after dinner hours, mostly).
As others stated you are not connected to your own router you are picking up your providers hotspot but so are a zillion other people cluttering the network. Sometimes providers have timeouts and kick you off, other times it's traffic and sometimes it's your distance from their signal, in which case an Alfa wifi adapter will help get you better stronger more solid connections, however some tablets have trouble connecting those wifi adapters or installing their drivers.
In fact your settings might be affecting your steady connection, research how to correct your wifi settings or download a automated software program the searches your settings and recommends new settings.
With Phone tower data and Wifi signals placement and direction of your device can make a huge difference as well.