Can't make IP7000 mics works when mobile phone is connected with external 2,5 jack

Hello Team,

for demo purpose i try to use sounstation IP 7000 with a cell phone connected through 2,5 jack external port

unfortunately sounds in works but sounds out doesn't ie : i get the audio from the distant caller on the IP 7000 loud speaker and it sounds good but the distant caller hear me very weakly because my voice is catched by the cellphone mic instead of the soudstation mics.

i ve tried with an iphone and a galaxy, issue remains.

my setting are : Aux Audio IN / Other Input ( but same results with Wireless Mic or Off checked )

nb : when i play music from the cell phone it works and is played back on the soudstation loud speaker.( pictures attached )

any ideas ?

regards Pierre