Hi all i am having a strange issue with internal calls.
I have 3 companies at 3 different locations.
2 locations have 2 pbx (m8l location B & m32X Location A) that communicate with each other through cisco vpn.
The last location C is located in a another country and uses x-lite to make internal calls.

the main site (HQ) has the M32x and when making internal calls to location B & C and vice versa everything works fine.
But when i call from location B to location C, location C can hear me at location B, but I can't hear them.
When location C does call location B, we can hear and talk to each other.

I have checked my codecs, and they all seem to be correct.

Does anyone have an idea, what else could be wrong?