Hisense TV Hacked?

Using Xfinity Stream on a Hisense TV, via Firestick. While waiting for the late-night news to come on, the game show Password was on. Then the TV cut out (not off) to a black screen, when a voice came through the speaker that said, “they are watching some game show.” And then the Xfinity app/TV programming came back up as if nothing happened.

Shortly before, WiFi began to drag on other devices in the house. Something was definitely wrong here. Two listed devices were unfamiliar, a Roku device and a “Hon Hai Precision” (Google says that could be literally anything).

We’ve since disconnected the router, renamed/changed password, kicked all devices off. But is there anything else we should do? Kind of freaked out.