Dog Question

We have a large backyard that is fenced about eight feet tall to visualize.

We have two dogs and we play with them fetch and run around the backyard they both run play chase each other and have dog toys.

They live indoors sleep indoors we have nice dog beds for them.

When they are outside we have buckets full of water for them to drink and dog houses outside for them to nap

One dog he's neutered he's a medium or large dog breed he keeps jumping the fence and leaving comes back

The problem is we are concerned why is he leaving and afraid for the neighbors he doesn't bite anyone.

What can we do to help him he gets Lot's of love being pet, walks gets treats we play w him. What is going on

It has been suggested we take to a shelter or pound because of constant escaping jumping over the wooden fence