meg0m 

Sooo ... having finished a nice serving of crow, I can report that Eero tech support did a fantastic job troubleshooting this issue with me this morning. Issue looks to be with Apple, at least in my circumstance. Appears to be an issue with the iPhone OS not updating properly for advertised audio interfaces. For example, at some point this morning, airplay devices disappeared from the audio airplay list on my iPhone (X in this case). All devices were available and worked on my computers and iPad. Despite the audio interfaces not displaying, my Apple TV did display in the iPhone's Airplay Control Center overlay, and I could control the Apple TV and see updated information from it in the overlay. Multiple restarts of the network made no difference on the iPhone. Turning the iPhone's Wifi on and off made not difference.

Finally, we shut down and restarted the iPhone. Everything displays and works as expected. For the past 1.5 hours, everything has remained correct.

The Eero tech rep did correct some config settings that were not optimal. He also made ip reservations for all of my airplay devices in the hopes that the problem may be caused by updates from airplay devices for which the iPhone does not refresh.

Anyway, after my slagging on Eero, I am happy to report that my doubt in Eero was unfounded.

overall i do like the product.   a few issues other than airplay

i pay for eero plus and can't whitelist a site (and depending on browser/os, a site can be blocked without me having any way to see that it is eero blocking it).  my only workaround to get to the legit site is to turn off most of that kind of protection...  fortunately for the latest one i tried 5 different browers on 3 computers and one of them finally gave me the eero plus screen instead of an SSL error, which is an issue eero should fix  

limited customizability/configurability, no command line.  i had to get rid of my $150 adblock device because there was no way to connect to the eero and then connect to the device (it sits upstream of the eero, and if eero isn't connected to internet, you can't manage eero at all).  fortunately they added adblocking support and fortunately pihole can sit in parallel of a network unlike the previous one (adtrap).

hard to troubleshoot when stuff doesn't just work (like above, if not connected to internet can't even connect to it to relay to other devices or test)

the password management app in eero plus has a garbage interface compared to lastpass, and the vpn they offer is only in beta on windows, and isn't as smooth as expressvpn.  i wouldn't be surprised if those companies paid eero to more or less advertise for themselves, instead of eero adding more value by using plus user revenue.  

yroc I agree with your critiques. The Eero UI has been designed too much for users who know nothing and have no interest/ability to customize to their real needs. Given how long Eero has been running, it seems way overdue to provide some level of "Advanced" options. God forbid anything beyond the iPhone app.

One comment during my call today was a bit irksome. The rep criticized Apple's history of doing proprietary stuff with their network stack. Talk about pot calling kettle black.

Anyway,   yroc  Luis and jamois comments all are good reminders that my particular solution today (1) does not confirm that eero is not at fault or a major contributor to this problem and (2) may not last :).

Luis  makes an especially good point that, just because one service (eg, remote control of appletv) may be broadcast successfully, airplay may not. Rrrrrrrr. What happened to "it just works"? The impossible dream.