IPsec Phase 2 Issue | No decaps but with Encap?

Hi Guys, Recently encountered an issue in where Phase 2 of IPsec somehow not functioning well. the issue is I can see encapsulated data but not able to decapsulate any data traffic.

Issue:

#pkts encaps: 5413, #pkts encrypt: 0, #pkts digest: 0
#pkts decaps: 0, #pkts decrypt: 0, #pkts verify: 0

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I ran a debug and I'm able to see this issue "delete SA with spi","not sending KEY_ENGINE_DELETE_SAS", "deleting SA".

Apr 12 10:53:52.057 GMT: IPSEC(key_engine): got a queue event with 1 KMI message(s) Apr 12 10:53:52.057 GMT: IDB is NULL : in crypto_ipsec_key_engine_delete_sas (), 6145 Apr 12 10:53:52.057 GMT: IPSEC(key_engine_delete_sas): rec'd delete notify from ISAKMP Apr 12 10:53:52.057 GMT: IPSEC(key_engine_delete_sas): delete SA with spi 0x386CD8DD proto 50 for 220.20.20.20 Apr 12 10:53:52.057 GMT: IPSEC(delete_sa): deleting SA, (sa) sa_dest= 122.1.1.1, sa_proto= 50, sa_spi= 0x3DFBF9A5(1039923621), sa_trans= esp-aes 256 esp-sha-hmac , sa_conn_id= 11505 sa_lifetime(k/sec)= (4608000/3600), (identity) local= 122.1.1.1:0, remote= 220.20.20.20:0, local_proxy= 122.1.1.1/255.255.255.255/47/0, remote_proxy= 220.20.20.20/255.255.255.255/47/0 Apr 12 10:53:52.058 GMT: IPSEC(delete_sa): deleting SA, (sa) sa_dest= 220.20.20.20, sa_proto= 50, sa_spi= 0x386CD8DD(946657501), sa_trans= esp-aes 256 esp-sha-hmac , sa_conn_id= 11506 sa_lifetime(k/sec)= (4608000/3600), (identity) local= 122.1.1.1:0, remote= 220.20.20.20:0, local_proxy= 122.1.1.1/255.255.255.255/47/0, remote_proxy= 220.20.20.20/255.255.255.255/47/0 Apr 12 10:53:52.058 GMT: IPSEC(send_delete_notify_kmi): not sending KEY_ENGINE_DELETE_SAS ! Apr 12 10:53:52.059 GMT: ipsec_out_sa_hash_idx: sa=0x7F00A631CA58, hash_idx=872, port=500/500, addr=0x3ECCF1BA/0xC6234A03 Apr 12 10:53:52.062 GMT: IPSEC(ident_delete_notify_kmi): Failed to send KEY_ENG_DELETE_SAS Apr 12 10:53:52.062 GMT: IPSEC(ident_update_final_flow_stats): Collect Final Stats and update MIB IPSEC get IKMP peer index from peer 0x7F00A631A660 ikmp handle 0x4007E5B8 IPSEC IKMP peer index 0 [ident_update_final_flow_stats] : Flow delete complete event received for flow id 0x24002521,peer index 0 Apr 12 10:53:53.039 GMT: %CRYPTO-6-IKMP_NO_ID_CERT_FQDN_MATCH: (NOT ERROR BUT WARNING ONLY)ID of <> (type 2) and certificate fqdn with <>.com Apr 12 10:53:53.039 GMT: %CRYPTO-6-IKMP_NO_ID_CERT_FQDN_MATCH: (NOT ERROR BUT WARNING ONLY)ID of <> (type 2) and certificate fqdn with <>.com Apr 12 10:53:53.041 GMT: IPSEC(key_engine): got a queue event with 1 KMI message(s) Apr 12 10:53:53.041 GMT: IPSEC(key_engine): got a queue event with 1 KMI message(s) Apr 12 10:53:57.233 GMT: IPSEC(key_engine): got a queue event with 1 KMI message(s) Apr 12 10:53:57.233 GMT: IDB is NULL : in crypto_ipsec_key_engine_delete_sas (), 6145 Apr 12 10:53:57.233 GMT: IPSEC(key_engine_delete_sas): rec'd delete notify from ISAKMP Apr 12 10:53:57.233 GMT: IPSEC(key_engine_delete_sas): delete SA with spi 0x8CCC617 proto 50 for 60.2.2.2 Apr 12 10:53:57.233 GMT: IPSEC(delete_sa): deleting SA, (sa) sa_dest= 122.1.1.1, sa_proto= 50, sa_spi= 0x78F35D03(2029214979), sa_trans= esp-aes 256 esp-sha-hmac , sa_conn_id= 11507 sa_lifetime(k/sec)= (4608000/3600), (identity) local= 122.1.1.1:0, remote= 60.2.2.2:0, local_proxy= 122.1.1.1/255.255.255.255/47/0, remote_proxy= 60.2.2.2/255.255.255.255/47/0 Apr 12 10:53:57.234 GMT: IPSEC(delete_sa): deleting SA, (sa) sa_dest= 60.2.2.2, sa_proto= 50, sa_spi= 0x8CCC617(147637783), sa_trans= esp-aes 256 esp-sha-hmac , sa_conn_id= 11508 sa_lifetime(k/sec)= (4608000/3600), (identity) local= 122.1.1.1:0, remote= 60.2.2.2:0, local_proxy= 122.1.1.1/255.255.255.255/47/0, remote_proxy= 60.2.2.2/255.255.255.255/47/0 

I resolve the issue by disabling the tunnel interface for several minutes after enabling again IPSec session went up both phase 1 and phase is working. Note: we have multiple tunnels configured and both experienced the same issue in when Phase 2 is not fully working. We are using cisco router 4k series btw.

Have you encountered this issue and what could cause the issue? Is this issue normal? Thanks