IPSEC connection between SIP Client and PCSCF. ESP header does not appear. IPsec does not apply to the header

I am creating SIPp script to create scenario for establishing IPSEC connection between UE and PCSCF.
When I am sending 2nd Register from secured UE client port to PCSCF secured server port, it is not sending in ESP packet. IPSEC is not getting applied although SA has been created which I have verified using setkey -D.

setkey -c << EOF
spdadd $pcscf/32[$port_pc] $ue/32[$port_us] tcp -P in ipsec esp/transport//require ;
spdadd $pcscf/32[$port_pc] $ue/32[$port_us] udp -P in ipsec esp/transport//require ;
add $pcscf $ue esp $spi_us -m transport -E $ealg $ck -A $alg $ik
EOF

4 SA's has been already created

192.168.137.98 192.168.137.39 
    esp mode=transport spi=1024(0x00000400) reqid=16625(0x000040f1)
    E: 3des-cbc  d0c1e6cd d58c07f7 fe4a6715 83d60210 d0c1e6cd d58c07f7
    A: hmac-md5  320fe4a8 ab88a62d f406ccb9 76346602
    seq=0x00000000 replay=4 flags=0x00000000 state=mature 
    created: Jun 24 17:01:11 2019   current: Jun 24 17:01:22 2019
    diff: 11(s) hard: 0(s)  soft: 0(s)
    last:                       hard: 0(s)  soft: 0(s)
    current: 0(bytes)   hard: 0(bytes)  soft: 0(bytes)
    allocated: 0    hard: 0 soft: 0
    sadb_seq=1 pid=9623 refcnt=0
192.168.137.98 192.168.137.39 
    esp mode=transport spi=2048(0x00000800) reqid=16624(0x000040f0)
    E: 3des-cbc  d0c1e6cd d58c07f7 fe4a6715 83d60210 d0c1e6cd d58c07f7
    A: hmac-md5  320fe4a8 ab88a62d f406ccb9 76346602
    seq=0x00000000 replay=4 flags=0x00000000 state=mature 
    created: Jun 24 17:01:11 2019   current: Jun 24 17:01:22 2019
    diff: 11(s) hard: 0(s)  soft: 0(s)
    last:                       hard: 0(s)  soft: 0(s)
    current: 0(bytes)   hard: 0(bytes)  soft: 0(bytes)
    allocated: 0    hard: 0 soft: 0
    sadb_seq=2 pid=9623 refcnt=0
192.168.137.39 192.168.137.98 
    esp mode=transport spi=147047421(0x08c3c3fd) reqid=16623(0x000040ef)
    E: 3des-cbc  d0c1e6cd d58c07f7 fe4a6715 83d60210 d0c1e6cd d58c07f7
    A: hmac-md5  320fe4a8 ab88a62d f406ccb9 76346602
    seq=0x00000000 replay=4 flags=0x00000000 state=mature 
    created: Jun 24 17:01:11 2019   current: Jun 24 17:01:22 2019
    diff: 11(s) hard: 0(s)  soft: 0(s)
    last:                       hard: 0(s)  soft: 0(s)
    current: 0(bytes)   hard: 0(bytes)  soft: 0(bytes)
    allocated: 0    hard: 0 soft: 0
    sadb_seq=3 pid=9623 refcnt=0
192.168.137.39 192.168.137.98 
    esp mode=transport spi=70783604(0x04381274) reqid=16622(0x000040ee)
    E: 3des-cbc  d0c1e6cd d58c07f7 fe4a6715 83d60210 d0c1e6cd d58c07f7
    A: hmac-md5  320fe4a8 ab88a62d f406ccb9 76346602
    seq=0x00000000 replay=4 flags=0x00000000 state=mature 
    created: Jun 24 17:01:11 2019   current: Jun 24 17:01:22 2019
    diff: 11(s) hard: 0(s)  soft: 0(s)
    last:                       hard: 0(s)  soft: 0(s)
    current: 0(bytes)   hard: 0(bytes)  soft: 0(bytes)
    allocated: 0    hard: 0 soft: 0
    sadb_seq=0 pid=9623 refcnt=0