Upgrading Reminders

Yesterday I took the plunge and upgraded my iMac to Catalina. The main thing holding me back was having time to review my old photos and videos to update any based on outdated codecs.

My iPhone and iPad have been on iOS 13 since last year. I’ve been trying to upgrade my Reminders app but each time it seems to go through a process of doing something or other and then reverts back to where it was before with the upgrade button once again visible.

What’s the secret to to successfully upgrade reminders?