One Way Speech Path

[Quayfour - MTL]

I have an issue with a one way speech path on a hosted 3CX installation.
Extension to Extension on the 3CX app (iPhone)
The Called Party can be heard but they cannot hear the calling party.

 

[TheodorosG_3CX]

The issue is only with the iphone app?
Also you have the issue on both WiFi and mobile data connection?