UE 5.5 - Online Subsystem 'Join Session' always results in `On Failure`

Thanks for getting back on this and making the changes so quickly.
I’ve validated the latest binaries from the master branch in the 5.5 version of my project and it all works as expected now.

Hopefully Epic can sort out all of the Steam interface issues so we won’t need these workarounds in future!

Just in case anyone is unsure (or didn’t get the plugin from GitHub), the master branch binaries are here: