lane & chickadee -- thank you. I am open to any suggestions! I am embarrassed to say how ridiculously easy my email address is. I have three, and they do not use any oddball characters. I got these Fastmail accounts back in the Stone Age.
I will be contacting support. I'll let you know what they said. I, too (as a long-time user of this service), have noticed certain changes. Things aren't as "tidy" as they used to be. A certain laxity that is really inconvenient.