iLBC codec conversion issue

Hi all,

we are experiencing problems when using the iLBC codec. iLBC to iLBC calls are OK, also G711 to G711 are fine, the conversation is clear. But if we get call which needs to be converted between iLBC and G711 there is one way robotic sound. Voice from iLBC to G711 is fine, the other direction G711 to iLBC sounds very robotic.
Any clue why or what we can do about it?

Thank you for your help.

Nobody came across this problem? Do you use iLBC codecs without issues?