I’ve since deleted my approximately 40 essential notification rules. Then I created new rules for my wife, daughter-in-law, and both sons, and sent myself messages (WhatsApp and email) using my wife’s phone. Everything works. The Glyph Matrix displays my wife when a message arrives. Then I create more rules for friends, calendar, and so on. I tested it again in between, and it works. Then at some point, it stops working. The ringing bell only plays for a few seconds. Changing the existing rule for my wife doesn’t help. However, if I delete and recreate her rule, it works for her again. I would have to do the same for my daughter-in-law and sons. It’s a vicious cycle. I suspect the Glyph interface only allows a certain number of rules.