Mission goes forward. Acts 13 Why did Jo

Mission goes forward.
Acts 13
Why did John return to Jerusalem?
We learn later how Paul saw the severity of this referring to it as desertion.
So was it because of fear for being a missionary?
Was John simply homesick?
Or did he have a problem with Paul’s leadership?
We are not told, just that he returned home.
Luke teaches us that it is not always necessary to air our dirty washing in public or other people’s for that matter. Just say what needs to be said. Sometimes less is better. Not everyone needs to know the details.
In actual fact when fewer people know the reasons for the failure then it is easier when the fallen is restored as John Mark was.
Just say the bare facts and move on.