Court appoints executor; the will found in safe box names a different executor (USA)

Question

Someone dies and their will cannot be found. Two people petition the court to be the executor. They do not get along and do not want to be co-executors.

The court appoints one of them to be the executor. That person accesses the safe box at the bank. The will inside the safe box names the other person (or possibly someone else not yet involved) to be the executor.

What happens next?

If this is dependent on the state, the state of interest is Utah.

Note: This question was triggered by another thread that mentioned the perils of safe boxes for storing wills, Prevent a will from being overlooked

Answer 1

If the will is valid, the named executor is the executor

Technically, the person appointed by the court is an administrator, not an executor. The correct course of action is for them to notify the court and ask for probate to be granted to the named executor to replace the letters of administration.