After disabling Google account and re-enable account duplicate Birthday events in calendar

After disabling contacts from google account the birthday entries in calenadar app doesn't be removed from the calendar app. After enabling contacts from google account I have two birthday entries for each contact in calendar. I tried this several times, now I have 5 birthday entries for each contact in calendar. I use iOS13 on my iPhone SE.

When I click on the wrong entries a empty screen appears, except for the last entry which is correct, this show the contact details.

How can I empty the cache of the calendar app? Deleting and reinstallation doesn't help. I don't want to wipe my phone!