I don't know how to help you... On my Q3S, I have 2 accounts. First have the new icon, but the second have the unknown sources in the list... So weird too but the fact is I have access to unknown sources on both of my accounts... You should try to google that or to do a factory reset. There seems to be a Meta bug on your headset...
Anyway, if you find a solution, please tell me, I'm curious