Any idea why Mosh isn't wearing her engagement ring any more?

IMHO it's no indication for anything going on as both, Mosh and Fred, look relaxed of lately...
I often wear just my wedding band, especially on the weekends. I never wear my rings around the house, or to the gym and places like that.
I don’t think there’s a “reason”. Maybe it needed to go to the jewellers? With white gold, every few years it needs to be re-plated (I can’t remember if Mosh’s ring is WG or platinum?), or maybe just a clean and check the settings. Maybe she just didn’t feel like wearing it? She is wearing her wedding band (not a different ring).