Apple TV app randomly fails to load content

I do not know how to reproduce this because it happens randomly. I have noticed it on other content like Music and Fitness+, but mostly on TV because I use it the most. After talking to senior Apple TV support staff twice, they told me it is due to my networking equipment blocking the ports that Apple uses. However, I do not have any firewall enabled or other security tools on my Orbi router or AT&T gateway. I seemed to get better results by wiring directly to my gateway rather than the Orbi router, but content stopped playing at least once in that setup so far. IP passthrough on the gateway to the router did not help. I believe the problem is with Apple, but they haven’t admitted it yet. They claim to use custom ports that some firewalls will block. I don’t buy it. They publish the list of ports they use, and they seem standard. Also, why wouldn’t other streaming services use similar ports? And why aren’t the ports blocked all the time instead of on and off?