Ah, of course, I remember now; I need to tell the client, the browser, to behave itself. I’ve used the relevant cache-control fields before, many years ago. I think I need to talk to our friend Mr Johnson about it and see what he says.
I need some help in working out whether it really is a caching effect that I’m seeing and not some other buggy thing, but I can’t see how it can be a fault in my code, as I run the program, see the badness, then run the program again, and second time of execution all is well. And my code has no persistent storage in it; no file io, for example. Do you agree with my logic in this argument ? Alternatively, it could be some very weird bug in Shortcuts itself, so actually I might just ignore it until iOS 16 comes out, just in case there is a relevant known Shortcuts bug that gets fixed, and then I won’t have wasted anyone’s time debugging.