How to sync iOS reminders with iCloud?

Question

iOS

iOS 13.4 The Reminders app has been updated.
No reminders are synced on icloud.com/reminders, although the calendar and notes are synced.

spoiler

Answer 1

In a similar situation, I managed to partially solve the problem by deleting completed reminders. Somewhere I found a siri shortcut that does this, however, no more than 146 pieces in one run. There's also a problem with apple reminders that they didn't admit to, but try this first)