A few weeks ago, a security issue was revealed affecting Group FaceTime calling. This problem allowed the callers, remotely pick up the call they were making when adding themselves to the group call, a bug that also occurred if the recipient of the call used the volume down button to silence the terminal.
Apple proceeded disable group calling service for almost 10 days, until it released the corresponding iOS update that solved this problem: iOS 12.1.4. With the release of iOS 12.1.4, Apple re-enabled group calling only on devices that were updated to the latest version, as iOS 12.1.3 is where this security issue lies.
Apple released a patch that, although it is true, solved the security problem that it presented, it seems that the solution it has been a patch. Currently, if we make a group call with all the interlocutors who have to be part of the call, we will not find any operational problems.
However, if we try to add an interlocutor to a call that is already in progress, we will be able to use the Add people button, since it is grayed out without the possibility of being pressed at any time. In this way, if we want to make a group call we have to do it from the beginning, since we will not find the option to add new interlocutors.
As expected, Apple has already ruled on the matter through its support account. According to Apple, group calls need to be made from the beginning with two or more parties. Before the security problem, Apple allowed us to add people to an already started call, as we can do in any other service, both calls and group video calls available today.
Presumably in future iOS updates, Apple releases a new patch that actually fixes the security problem that was detected And forget about the patch that they have released that really is useless.