Symptom:
488 Not Acceptable Media stats incorrect

Conditions:
Configure the following in DUT:

conf
context scscf
cscf ifc-spt-group id 130
spt-condition id 2
exit
cscf ifc-spt-group id 140
spt-condition id 2
end

conf
context scscf
cscf service servingcscf
custom response ue-capability-failure msg reject response-code 488

1.Register 2 users.
./mistle -node UAC -category ims_sim_main_testcases -testcase REG -userConfig HEADER1==P-Access-Network-Info HEADER1_VALUE=="3GPP-E-UTRAN-FDD;utran-cell-id-3gpp=00000000" HEADER2==Contact  HEADER2_VALUE=="<sip:010244411801@192.168.105.1:7001>;+g.3gpp.smsip" -node AS -category ims_sim_main_testcases -testcase REG_AS -type sim_as  -fsm 1

./mistle -node UAS -category ims_sim_main_testcases -testcase REG -userConfig HEADER1==P-Access-Network-Info HEADER1_VALUE=="3GPP-E-UTRAN-FDD;utran-cell-id-3gpp=00000000" HEADER2==Contact  HEADER2_VALUE=="<sip:010244411811@192.168.105.1:9001>;+g.3gpp.icsi-ref=\"urn%3Aurn-7%3A3gpp-service.ims.icsi.mmtel\"" -node AS1 -category ims_sim_main_testcases -testcase REG_AS -type sim_as  -fsm 1


2. Send MESSAGE with 488 Response. 
./mistle -node UAC -testcase MESSAGE_GENERIC_4XX_C -userConfig RESPONSE==488 PACKET==MESSAGE HEADER1==P-Access-Network-Info HEADER1_VALUE=="3GPP-E-UTRAN-FDD;utran-cell-id-3gpp=00000000" HEADER2==Accept-Contact  HEADER2_VALUE=="*;+g.3gpp.smsip" -node AS -testcase MSG1_AS_488_PROXY -type sim_as -fsm 1 -node AS1 -testcase MSG1_AS_488_PROXY -type sim_as -fsm 1

3. Check "488 Not Acceptable Media" response counter using the following CLI in SCSCF service.
show cscf service custom statistics name servingcscf call-type msg

Transmitted counter should have been incremented to 2 but it is incremented to 1.

Trace & Debug logs attached.