Copy iCloud Link in iOS Stopped Working

Every day, for several years now, at the end of the day I do the same thing in Photos on my iPhone: I select all the photos I have taken that day, click on the icon of the box with an arrow, and choose the menu item "Copy iCloud Link". After a few seconds (occasionally it takes a minute or two) it completes and I have a link on my clipboard to those photos that I can email. Starting yesterday evening, that process no longer completes: once I choose the menu item I get a dialog box that says, "Preparing iCloud Link…" (normal) and a spinning Walmart-logo-lookalike spinner thingie (also normal), but the spinner never stops, and the link is never prepared. I have tried completely restarting my iPhone, but it doesn't make any difference. I am properly logged in to iCloud and I haven't done anything differently from what I always do, so something else has changed that needs to be reset and I can't figure out what it is. I need some suggestions as to what else to try.

Thank you.