By default, pjsip listens on UDP port 5060 and chan_sip is on port 5160. Assuming you haven’t changed these, it appears that the GXW is sending incoming calls to port 5060 so they are being seen by pjsip, which does not recognize them.
Assuming that you want to keep using chan_sip, in the GXW, change SIP Server for the account from
192.168.1.144
to
192.168.1.144:5160