Ghost alarm from data transfer

Two years ago I bought a new IPhone (12 mini) and I transfer the data from the old IPhone 5.

When I did the backup of iPhone 5 in order to transfer it on the new IPhone, I DID NOT cancel the alarm clock (big mistake).

Starting from then a Ghost alarm clock ring everyday. This alarm is related to the Sleep function.

To try to eliminate this alarm I switch off everything, all sleep functions, also all the other alarms but nothing. This Ghost alarm still in some remote memory of the IPhone.

There is anyone that can suggest a way in order to get rid of it?

I was also thinking to do a new backup of the old Iphone 5 after removing the alarm, and loading it in the new IPhone 12mini, but then I will lose all new informations, unless you can suggest a way to not to lose them.

Every help is really appreciated.

Thank you