iOS Calender resets reminder to „no reminder“

Hi there,

when I create any event in the calendar and set the reminder to standard (in my case 5 minutes before event), it works well. But as soon as I move that specific event to another day and save it, it sets the reminder to „no reminder“. (during saving, it still shows the reminder setting to 5 min, it shows the „no reminder“ after I reopen the event)

Has anyone an idea what’s going on there?

By the way, this happend in iOS 17 and still persists in iOS 18