Friend Instantly Disconnects When Joining Any Instance I Host (Hideout, Maps, Zones)

My brother and I are playing Path of Exile 2, and we’ve encountered a persistent co-op issue: he disconnects immediately when joining any instance I host, whether it’s my hideout, maps, or any regular zone I entered first.

🔄 Issue Summary:
If I host an instance (hideout, map, or overworld area), my brother disconnects instantly upon trying to join me.

This includes:

My hideout

Maps I open in the Map Device

Even campaign zones or towns if I enter first

However, I can join his instances without any issues.

We’ve tested this on multiple characters and multiple sessions, always with the same results.

🧪 Troubleshooting We've Done:
Uninstalled and reinstalled the game on both systems.

Tested using both the Steam client and the standalone client—issue persists in both.

Switched hideout layouts to create new instances.

Cleared shader and minimap caches.

Verified game files.

Disabled overlays, VPNs, and background apps.

Verified no firewall or NAT issues.

Tried different characters and hideouts—no change.