Call Pick Up Issues

Hi, I´m having trouble with the call pick up feature on Yealink T46G/T28 phones

Behavior is very similar to this thread Call Pick Up Issues on T20
For some reason broadworks sends "BYE" few seconds after sending "200 OK" with SDP, causing the phones to drop the call.

To make things weird, I tested with lattest non-broadsoft firmware on a T46G an the issue becomes more or less random (T28 won´t work no matter what firmware). I attached a Image with bow flows
  works_sometimes.png (Size: 19.23 KB / Downloads: 6) , as you can see on left flow the call pick up feature works but on the left flow it fails, those test were made one after another

I have attached pcap, syslog and config.bin of a T46G (
  t46g.zip (Size: 81.96 KB / Downloads: 1) ) this was using firmware recommended by Broadsoft Partner configuration guide and call pick up not working

I also attached pcap of same t46g with newer firmware on which call pick up features works randomly (
  t46_callpickup_working_randomly.pcap (Size: 108.77 KB / Downloads: 1) )

Thanks in advance