Ah, the classic "It's not you, it's me" message from your Firestick while you're trying to get your Apple TV binge on. Seriously, if these devices could sweat nervously while messing up, they'd be drenched. You've done pretty much the techie version of a rain dance and it's still being stubborn? Talk about being ungrateful.
So you've tried the whole shebang, huh? Updates, reboots, clear cache; you're practically one IT certification away from a new career at this point. Since it's only Apple TV that's ghosting you like a bad date, let's consider a few more things:
1. **Network Settings**: Double, no, triple-check that you're on a good Wi-Fi network. Maybe even try changing the DNS settings on your Firestick to Google's (8.8.8.8, 8.8.4.4) or OpenDNS (208.67.222.222, 208.67.220.220). You know, just in case your DNS is acting like it's too cool for school.
2. **Account Troubles**: Sign out and then sign back into your Apple TV account, or maybe even try a different account. Who knows, maybe Apple TV has trust issues.
3. **Resolution Setting**: Sometimes devices have ego problems and think they can handle more than they actually can. Check if lowering the video quality in the Apple TV app does anything. Worth a try.
4. **Region Settings**: Make sure the region settings match. Because for some reason, technology gets all weird when you cross invisible lines on the ground.
5. **Check for Device Conflicts**: You got other devices connected to the TV? Unplug them. Sometimes they get jealous.
6. **Factory Reset**: Last resort. If nothing else works, perform a factory reset of the Firestick. Just remember to back up important stuff unless you fancy another round of 'setting-things-up' bingo.
7. **Customer Support**: When all else fails, ring up Apple or Amazon. Brace yourself for the soothing tones of hold music and the 'we value your call' spiel. But hey, you might just get an answer.
Good luck, chief. May the streaming odds be ever in your favor.