Thanks for pointing this out. This is key. I noticed that one battery would eventually climb from like 10% to 30% during the day. I charged up both batteries and now they are staying in the green.
It does appear that Ring has addressed the issue. But what poor communication about the whole thing. I was thinking of converting my legacy home security system over to Ring, but not after this incident. The chance that one errant software update could disable my whole security system is just not worth it.