iPhone Revert Reminders database after upgrade?

[pk0]

When first launching Reminders after the iOS13 update, it asked if I would like to update the Reminders database. I picked yes to see the new features but now my iPad(not on iOS13) does not sync properly. Has anyone found a way to downgrade the database? If I reverted to iOS12 and then upgraded again, would it start syncing with iOS12 again?

I tried uninstalling and re-installing the Reminders app on iOS13 but that didn't fix it.

 

[pk0]

I tried a few things without luck. It looks like once you commit to upgrading the Reminders database, there is no going back.

I restored my phone iOS 12.3.1 and created my lists in Reminders. Then I upgraded to iOS 13 again and it didn't prompt to upgrade again nor were my lists there(they still show on my iPad running iOS 12.3.1 though).

Then I went to icloud.com and tried doing a recovery of Reminders back before iOS 13 and then wiped out my phone but had the same results.

 

[macintoshmac]

It was pretty clear that if one chooses upgrade, the upgrade is done for life.

 

[Shirasaki]

This is basically the same thing back in iOS 9 when the notes app got a major upgrade. One way trip. Typical Apple.
I saw the prompt too but tapped no.