okay, found the hint in the stores days before. forgot to reply.
but how should it be possible to stream to e.g. youtube/twitch/instagram!? or whatever, when the goggles only supports hotspot instead of client?
You'd use mobile data from the phone.
when you think about it this makes sense, because streaming in the field will most likely rely on mobile data anyways
which phone and android (I suppose) version do you have? At least on Android 10 its definitely possible to use mobile Data while on Wifi. On my Oneplus there is even a setting in the wifi options to use mobile data when the wifi internet connection is bad.
i have an xperia x and i definitely have this option you've mentioned, but it never worked. it's on android 8.0.0...damn sony! i also have my iphones...