SIP response 484 "" after a SIP response 503

Trying to setup a failover trunk and getting a SIP resonse 484 “”. I;ve included the portion of the logs that shows the failover attempt and consequent 484 response. For some reason it seems the dialed number is removed from the string.

-- Executing [[email protected]:19] ExecIf("SIP/203-000001e2", "1?Set(CONNECTEDLINE(num,i)=9986342012)") in new stack
-- Executing [[email protected]:20] ExecIf("SIP/203-000001e2", "1?Set(CONNECTEDLINE(name,i)=CID:8242067)") in new stack
-- Executing [[email protected]ialout-trunk:21] ExecIf("SIP/203-000001e2", "0?Set(CONNECTEDLINE(name,i)=CID:(Hidden)8242067)") in new stack
-- Executing [[email protected]:22] GotoIf("SIP/203-000001e2", "0?customtrunk") in new stack
-- Executing [[email protected]:23] Dial("SIP/203-000001e2", "SIP/10016/9986342012,300,Tt") in new stack

== Using SIP RTP TOS bits 184
== Using SIP RTP CoS mark 5
– Called SIP/10016/9986342012
– Got SIP response 503 “Service Unavailable” back from xxxxxxxx:5060
– SIP/10016-000001e3 is circuit-busy
== Everyone is busy/congested at this time (1:0/1/0)
– Executing [[email protected]:24] NoOp(“SIP/203-000001e2”, “Dial failed for some reason with DIALSTATUS = CONGESTION and HANGUPCAUSE = 34”) in new stack
– Executing [[email protected]:25] GotoIf(“SIP/203-000001e2”, “1?continue,1:s-CONGESTION,1”) in new stack
– Goto (macro-dialout-trunk,continue,1)
– Executing [[email protected]:1] NoOp(“SIP/203-000001e2”, “TRUNK Dial failed due to CONGESTION HANGUPCAUSE: 34 - failing through to other trunks”) in new stack
– Executing [[email protected]:2] ExecIf(“SIP/203-000001e2”, “1?Set(CALLERID(number)=203)”) in new stack
– Executing [[email protected]:9] Set(“SIP/203-000001e2”, “CALLERID(all)=“CTI SI Branch” <203>”) in new stack
– Executing [[email protected]:10] Set(“SIP/203-000001e2”, “_KEEPCID=TRUE”) in new stack
– Executing [[email protected]:11] Goto(“SIP/203-000001e2”, “ext-trunk,7,1”) in new stack
– Goto (ext-trunk,7,1)
– Executing [[email protected]:1] Set(“SIP/203-000001e2”, “TDIAL_STRING=SIP/10015”) in new stack
– Executing [[email protected]:2] Set(“SIP/203-000001e2”, “DIAL_TRUNK=7”) in new stack
– Executing [[email protected]:3] Goto(“SIP/203-000001e2”, “ext-trunk,tdial,1”) in new stack
– Goto (ext-trunk,tdial,1)
– Executing [[email protected]:1] Set(“SIP/203-000001e2”, “OUTBOUND_GROUP=OUT_7”) in new stack
– Executing [[email protected]:2] GotoIf(“SIP/203-000001e2”, “0?nomax”) in new stack
– Executing [[email protected]:3] GotoIf(“SIP/203-000001e2”, “0?hangit”) in new stack
– Executing [[email protected]:4] ExecIf(“SIP/203-000001e2”, “0?Set(CALLERPRES(name-pres)=)”) in new stack
– Executing [[email protected]:5] ExecIf(“SIP/203-000001e2”, “0?Set(CALLERPRES(num-pres)=)”) in new stack
– Executing [[email protected]:6] Set(“SIP/203-000001e2”, “DIAL_NUMBER=”) in new stack
– Executing [[email protected]:7] GosubIf(“SIP/203-000001e2”, “0?sub-flp-7,s,1()”) in new stack
– Executing [[email protected]:8] Set(“SIP/203-000001e2”, “OUTNUM=”) in new stack
– Executing [[email protected]:9] Set(“SIP/203-000001e2”, “DIAL_TRUNK_OPTIONS=Tt”) in new stack
– Executing [[email protected]:10] Dial(“SIP/203-000001e2”, “SIP/10015/,300,Tt”) in new stack
== Using SIP RTP TOS bits 184
== Using SIP RTP CoS mark 5
– Called SIP/10015/
– Got SIP response 484 “” back from xxxxxxx:5060
== Everyone is busy/congested at this time (1:0/0/1)
– Executing [[email protected]:11] Set(“SIP/203-000001e2”, “CALLERID(number)=203”) in new stack
– Executing [[email protected]:12] Set(“SIP/203-000001e2”, “CALLERID(name)=CTI SI Branch”) in new stack
– Executing [[email protected]:13] Hangup("SIP/203-0000