Correct the work of the SIP client on android

Job ID: 36030052

Budget: $250 – $750 USD

Correct the work of the SIP client andoid app when returning from call hold.
The client receives the destination port over SDP, but the RTP traffic is sent to the old port (which was before the hold was initiated). As a result, the second party does not hear him. And it is necessary that RTP traffic be sent according to SDP.
SIP client is a stock desktop phone application (photo attached).
I have:
- the desk phone itself;
- root access via adb shell;
- application in the form of .apk file;
- .img firmware images.