As we're trying to keep compatibility with older versions of Godot, it may be that the OpenXR loaders version we're including in the binaries is too old for PICO 4.
That said, one known issue on the PICO 4 Ultra is that it doesn't correctly fall back to the PICO 4 action map entries. That shouldn't prevent it from starting but will prevent things from working. This is something that is being addressed.
Ok, looks like since we went up a version of the vendor plugin, we never adjusted the export settings to the new version. Thats probably why it was broken all this time. The 4.5.1 builds should fix it now *fingers crossed*
