iPhone, iPad on iOS 14.2 now upgraded to Catalina, upgrade reminders on iPhone and IPad, now lost

Further developments. While I still have only the reminder with a reference to a support page on my iPhone, my iPad and Mac now have the reminders. It would be helpful if there was some indication of them their restoration was in progress, but they have none the less seem now to have been restored. And now the iPhone is back. On the iPhone, I did get a dialog asking me to select whether I wanted reminders merged, but on none of my devices was there any indication that the restoration was in progress, they just appeared after a while. The fix was to turn Reminders off, then on again in iCloud. So if you do that, don't expect to get any feedback from the UI, but wait a bit, at you reminders will return.

This doesn't alter the fact that yesterday the reminders seem to be fine, but it may have been that they were being upgraded on iCloud, but not re-synced automatically, and with no feedback.