I recently had a similar situation with a device behaving much like you describe. The issue wasn't with the device, but rather a configuration in the WiFi Router. In some routers, parents can enable/disable certain parental controls that allow/prohibit certain things like streaming and other internet access at certain times of the day (for example: Mon - Fri at 9PM during the school year, which is the kiddos bedtime).
That having been said, are you absolutely sure someone hasn't been playing around with your WiFi router's configuration? Routers are configured via a web browser these days. Your issue sounds suspiciously like the issue I was having (I had forgot I had set up parental controls for the kiddos). Might be a worthwhile endeavor to check that possibility. The fact that your issue occurs every night at 8pm seems to imply this might be happening to you as well.
