Running 6.018, there's a minor problem with the "Avoid Pathing Through This Planet" control. I think it has to do with Team Control of ships.
When I select any non-main player Champion, the routing ignores the Avoid flag. This is expected, since I hadn't set that flag in those GUIs. It's not an issue, though, since including main player stuff in a group selection causes the flag to be correctly applied.
However, when I select a group including Champion 3 (that'd be the 4th player in the list), any pathing route will ignore the Avoid flag, no matter what else is in the group. The highlighted path on the Galaxy Map looks like it will apply the flag, but after clicking, the red highlighted line shows the true path (through the Avoid-flagged system).
In reverse, if Champion 3 has the avoid flag on a system and no other player does, Champion 3's flag overrides everyone else if included in a group.
In my testing, it's only Champion 3 that causes this.
I've attached a game where this can be easily demonstrated. In the Harkalenan system are all my Champions. The adjacent system Neijuash has a BHG and is marked as Avoid by the main player.
Try routing the Champions in various combinations from Harkalenan to the Yehatin system (marked as P7, slightly to the southeast).