question

I don't know what you think optimizenetwork() does, but it has nothing to do with the AGV navigator at all. The optimizenetwork() command recalculates the distance table of the Network navigator, as explained in its documentation. The distance table of the network navigator is how the network navigator's algorithm determines the shortest path from each network node to each other network node on the network. The AGV navigator is unaffected by this command at all.

When you give a travel command to an object using the AGV navigator, it always takes the shortest path from its current location to its destination. It does not account for routing around other agvs.

The left path is shorter than the right path, so that's the path it is going to take. If you want it to go down the right path first, then send it to a control point on that path first, or make the bottom path one-way.