Vaal Temple Co-Op Auto Close

In the past 2 weeks since patch 0.4.0d, gf and I have encountering some issues related to the Vaal temple in co-op.

Every time we enter the temple and either of us leaves the temple to transfer items to stash using the main entrance, we get an error "Failed to join instance because disconnected from server", the Vaal temple entrance is no longer open showing just the empty and black background triangle.

Before I continue listing other issues that may be related, I just want to confirm this is expected behavior in co-op, and not a bug.

I've read from several sources that players are meant to just take the most valuable items from the temple, and leave everything else behind. If this is the case then it makes sense why the temple closes after leaving.

But, I've also seen from other co-op gameplay how the temple shouldn't close as long as we don't leave the Vaal Temple area(not the temple itself), and don't manually close it, which is odd because on disconnect error(every time), despite not having lost connection at all, temple closes automatically.

Please let us know if there's a workaround for this issue, or if it's expected behavior to limit players from going back and forth to sell items dropped in the temple to Alva.

Worth noting:
- We both use waypoint -> 'Click to travel to the Vaal ruins' button to meet up and start the temple.
- We've tried 1 person uses waypoint(temple owner before opening), the other uses 'Teleport to this Player's Location' button to attempt different ways of dealing with this issue and nothing's worked.
- We've tried the other way around.
- We've tried using the portal on the map that got us the 6th energized crystal