Voices coming through soundbar after I turn off tv

I hear voices!

Seriously, this sounds strange but about four times over the last couple months I’ve heard a conversation or a voice coming through my soundbar or tv 1-5 minutes after I’ve turned it off. Not voices from tv show but kind of like a brief part of someone’s conversation. The first time I was brushing my teeth and I heard about 3 seconds of a man and woman talking like possibly a phone conversation. Couldn’t make out what they were saying as the water was running. Another time I heard someone say "listen". A couple other times I heard something but couldn’t make it out.

This has coincided with my tv randomly turning on slower than normal and  having the cable menu for the channel come up with a snow picture for a couple seconds then an audio pop followed by the picture coming on.

I have a Sony 85 inch LCD thats less than 2 years old and a Sony Z9F soundbar that’s wired to the tv and a Sony bluetooth sub. I have a box from Xfinity cable. My audio rig is not connected to any of the av gear listed above.

I’m wondering ifsomebody’s bluetooth signal is synching with the soundbar but that’s only a guess. It’s weird that it only happens randomly shortly after I turn the system off.

I’ve had two techs from Xfinity come out and they couldn’t find anything wrong. They did remove an unnecessary splitter outside and my picture got better.

Anyone heard of something like this or have an idea how to get to the bottom of it?