One Way Audio on Incoming Calls to Analog Extension


#1

We have a DAHDI card configured with 2 FXO ports (incoming POTS lines) and 2 FXS ports (one analog phone connected). In addition, we have some Polycom IP phones. We recently added the analog cordless phone and connected it via 1 of the FXS ports. The extension is configured, the trunks are configured and most things are working.

However, we have observed the following:
Receiving internal calls (from IP phones) to the analog extension results in one way audio. The analog extension cannot hear the caller. The caller can hear the analog extension user without issue.
Receiving external calls to the analog extension results in one way audio. The analog extension cannot hear the caller. The caller can hear the analog extension user without issue.

Also tested:
Analog extension initiates calls to internal extensions and both parties can hear each other.
Analog extension initiates calls to external numbers and both parties can hear each other.
IP phones initiate calls to other IP phones and both parties can hear each other.
IP phones initiate calls to external numbers and both parties can hear each other.
IP phones receive calls from external numbers and both parties can hear each other.

We are running FreePBX 14.0.13.40.

Any ideas what might be going on?

Thank you for any help you can provide!