Scripts

That's what I meant about script variables when loading a save file. Of course, I'm not talking about restarting (sorry for the unclear explanation, I'm prone to that).
I'll try a couple of experiments with this (different ways to save data) and report back. I'm just not very happy with "it works, and that's good enough"; I want to understand why it works. : )
Thank you for your patience and help.

Added 4 hours 3 minutes ago
Well, you were absolutely right.
Modern technology has clouded my mind. : )
When saving, the map creates its own "snapshot," so yes, all variables do indeed retain their values. I don't know how I tested it before, but I was convinced that there was a completely different principle at play.
Thank you for setting me straight.