Cannot see Grouped Echo devices

[pooh2dr]

I'm using Premium in the US on a Samsung Galaxy S9 with Android Pie (9) . Up until today had no difficulty connecting to an Echo speaker group via Amazon Alexa. There are 3 devices on this group. It previously appeared in my "devices available" as the group and would play throughout the house. Suddenly today it started out by refusing to connect to this group, and then eventually no longer sees the group listed in devices available. It can see the individual echo devices and I can connect and play to each one of them separately, but it cannot see the group any more. It's like Spotify "forgot a device", but I cannot find any way to make it see that "device" (in this case the group) any more. 

So far I've...

*verified both Alexa and Spotify are up to date

*Restarted both Alexa and Spotify

*Restarted the phone

*Disconnected Spotify from Alexa and reconnected

*Verified that the group works when playing Amazon music through Alexa

*Disconnected and reconnected the group, including renaming the group

*Connected other devices on my wifi that were not previously there (they appear just fine in "devices available")

ETA: I CAN see this group listed on my desktop option, but NOT my mobile app