Cubase with Facebook 360

I want to encode a 360° video (that I received from a client) with my ambisonic mix, and upload it to YouTube/Facebook.
For now, I’m trying to export a 360 ambisonic project. I used Facebook template with a 360° video. It works fine inside the project but I’m a little confused about how to export it properly, and how to encode it so that the sound will be affected properly by the viewer’s angle.
I’m exporting a b-format bus (TOA), but when I import it back to the project, I notice that only the first 2 channels are producing sound, and all the other 14 channels of the B-format are completely silenced.
Did someone here do it before and can help me with this?
I find that the information about that is quite limited.