I’ve got an Apple TV 4K, with software fully updated. But when it wakes from sleep each evening (my wife and I typically watch something over dinner), it usually won’t reconnect to the home wifi. I have to restart it; then it reconnects. Usually.
Any thoughts / suggestions?
When it’s in this not-connected state, does it think it’s connected to anything else?
I ask because of a common problem in Apple’s Wi-Fi (especially phones) where it won’t switch away from an established connection without explicit action.
For example, if I configure my phone for my home LAN’s SSID and also Comcast’s “XFINITY” connection (for Wi-Fi roaming), I end up with problems whenever I come home after going out. When driving through my neighborhood, it will connect to XFINITY, since it finds connections from neighbors’ routers, but when I get home, it remains on XFINITY (which has much less bandwidth than my own connection). It won’t switch away unless I explicitly change my connection.
This got so frustrating that I told the phone to forget the XFINITY service altogether (and removed Comcast’s security profile, since that makes sure XFINITY is always on the list of allowed networks).
I’m wondering if you might be experiencing something similar. If your home LAN is a bit flaky (or maybe gets disconnected when you run the microwave oven before dinner), then maybe your Apple TV ends up connecting to a neighbor’s public access point, meaning it won’t connect to yours without explicit action. If so, then the solution is to edit the list of acceptable SSIDs (if it’s available to edit) and remove all but your home LAN from the list.
No, it only has connection credentials for the one network.
Weirdly, if I check the network status when it’s in the state, it does show as connected to the home network; but it can’t (or won’t) actually contact anything.
Can’t you set the network priorities it connects to similar to the apple computer?
David
You can tell it not to sleep and just turn the TV off. I did that for awhile when we didn’t have a TV that turned on when the Apple TV turned on — I left the AppleTV on all of the time, but it didn’t really matter since the TV screen was off.
Not an ideal solution, but perhaps something to check out if nothing else seems to help.
Best idea I’ve heard so far 
Not in any way I know about. At least not through the normal iOS interface. If you share your keychain over iCloud, then all your devices share a common database of access points, but I don’t know if changing the priorities on a Mac will result in them changed on iOS devices.
But either way, it doesn’t matter. Once a device (Mac, phone, iPod, etc.) connects to an access point it will remain connected until it either loses signal or is manually disconnected by an operator. There’s no way to tell it “this is my preferred access point, so disconnect from anything else when it is in range”.
The priorities determine what will be selected when there is no active connection, and multiple access points are available to choose from. They don’t have any other effect on the system.
I have an older ATV that is connected to a hifi via HDMI cable (with splitter box to send video to a projector). I prefer to send audio to a pair of Homepods but need to keep the hifi in the system because some tvOS apps have terrible lip-sync with the Homepods. From this setup I know that the ATV always defaults to the HDMI when it wakes and I have to manually change to the Homepods.
My point is that a recent update to tvOS may be causing similar behaviour with your system - but it is defaulting to a non-existent audio output. Hence David C’s first question above.
I have my AppleTV connected directly to the TV via HDMI (with the TV’s audio return connected to the stereo system). No homepods to worry about because they’re not for sale here yet.
I’ll keep tinkering…