Alexa on Android app does not recieve calls

[qyo001]

Hello all ,
I am trying to play with Alexa-to-Alexa call , which is a great feature (so nice when someone from your home can call via Alexa directly to your Alexa installed on your Android device). But I am having issue with placing this call .
The outgoing call (from Android to Echo or to Apple's Alexa app) works without any issue. But any Incoming call (from Echo or from Alexa app installed someplace else just dropping.
Is that a known issue ? Any fix available ?
Thank you all for your help!