Old Calendar alerts went silent. New one worked.

iPhone SE. After finally updating to iOS Version 18.5, sound from calendar alerts went missing. I tried about seven setting changes to no avail. Added a new alert and that worked. Decided that stale data might be a possibility. Deleted the daily reminder and put it back as a new daily entry. The audible alert for the new entry worked today. I’ll be changing the remaining repeating, but silent, alerts soon.