Call from host support does not ring

[Ari-And-Susanna0]

It has been 4 or 5 times that airbnb support for hosts has been telling me that in order to answer my enquire they have called me and their number must be showing as "not answered call" on my phone. In fact, i see calls from +1 (USA) and I was wondering how come I missed thrm all.  The last one I just hapoened to have the mobile in hands and it simply did not last enough to start a very first sound when as ringing. Is anybody facing the same issue? Is it a bug issue?