League mechanics (Vaal / Ritual / Abyss) never spawn in local couch co-op

League mechanics not spawning and Act 3 crashes in couch co-op (same PC) – Patch 0.4

When playing Path of Exile 2 in couch co-op (two characters on the same PC), league mechanics never spawn, and Act 3 has severe progression and stability issues.

Both characters are in the same league (0.4). When each character is played solo, league mechanics (Vaal Temple, Ritual, Abyss) spawn normally and Act 3 works correctly.

When playing together on the same PC:

No league mechanics spawn at all (Vaal Temple, Rituals, Abyss, etc.)

In Act 3, the Vaal Temple cannot be opened/accessed

The game crashed twice during the Fire God boss encounter

These problems occur only in couch co-op, not in solo play

Changing Player 1 / Player 2 order does not resolve the issue. Both characters are in the same league and at appropriate progression levels. The issue is consistent and fully reproducible.

This appears to be a couch co-op specific bug where league mechanics are not initialized in instances and Act 3 content becomes unstable or inaccessible.