Q: i can't delete a reminder list

Ditto that.  I'm having the exact same problem.

I had the same problem. Renaming of a list would also be undone after a minute or so. I supposed that some background syncing with iCloud is causing these to reappear. So, I closed Reminders on my laptop, quit Reminders on my phone, and then logged in to iCloud via my browser, where I deleted the list. When I opened Reminders again on both my laptop and phone, the deleted list did not reappear. Effective, but irritating.

This doesnt work for me. I closed Reminders on all devices, and deleted the lists in the browser, but they reappeared after some seconds.

Same with renaming...