Upon further extensive testing there appears to be either a breaking change with ‘Join Session’ in Unreal Engine 5.5 OR Advanced Sessions plugin is somehow causing the issue.
I have tested the following:
- A brand new UE 5.5 project with minimal creation/join setup using the advanced session 5.5 binaries
- The same as above but for UE 5.4.4 with the 5-4-4 binaries. As far as I know, although the 5.5 binaries are published separetely on the site: Advanced Sessions Binaries – VR Expansion Plugin , they remain unchanged from the 5.4.4 binaries and are just rebuilt for the 5.5 version of the engine, so it seems like the issue is a change in the engine itself.
The exact same setup works flawlessly in UE 5.4.4 but not in UE 5.5.