I found the setting.OK, looks like this is using Automatic Content Recognition (ACR).
But it looks like the default is supposed to be disabled. Have you checked that? Uncheck "Use info from TV inputs"
https://support.roku.com/article/115005739288
Home screen - Settings - Privacy - Smart TV Experience - Privacy - uncheck Use Info from TV Inputs
I don't recall allowing anything, I guess they just slipped it in.