The focus of iOS 12 larger to improve the performance and stability of the system, and its most important features new support for FaceTime calls Collective up to 32 people, which suffered after that is a gap that the user’s privacy at risk.
Gap calls FaceTime Collective was called the listening party conversation the other when you make a call and before answering it, and so did Apple disable calls even fix the problem update iOS 12.1.4 which saw the return of the work group calls, but partially apparently.
Now, after the iOS update 12.1.4, when making a call with one party on FaceTime, can not add someone else to it, where the left button to add a person Gray is not effective.
The only way to add people to a call FaceTime is to start the call with at least two people, and it seems that Apple is on the lookout of the problem, but there is no information on the date resolved.
That’s good. Also, note that Group FaceTime calls need to be started with at least two additional users in the FaceTime app. Meet us in DM if you’re still having an issue with more users: https://t.co/GDrqU22YpT
— Apple Support (@AppleSupport) February 15, 2019
Finally, due to come solve the problem with the update iOS 12.2 which is currently still in the experimental stage.