First of all, I appologize if this question been asked in other post.
When doing transfer call from PSTN to another user using desktop app, the "Consult then transfer" works fine, even when transferring to external phone number (PSTN or mobile number). But when using Android mobile app, "Consult then transfer" can only using chat when the target is another MSTeams user (same domain/organization). There is no other options, it directly brings the chat.
I still can do "Consult then transfer" using voice from mobile app when transferring external number (PSTN/mobile) although that's the only logical way since I cant do chat to transfer call to such target.
Is this how it works/limitation when on mobile app?
I have the same issue, haven't found a solution or explanation yet. What I have tested is that when the chat window pops up, there is a white phone button on the right side of the name of the user you want to consult (above the black transfer button). If you press it, a call will be initiated and you can consult and then transfer. Still annoying that the functionality differs in the windows client and mobile client.