StrongSwan Tunnel Error Resolution

I'm facing an issue with my StrongSwan tunnel. I would appreciate a talented freelancer to assist in troubleshooting and resolving the problem.

Key Details:
- The error message I'm encountering is 'invalid HASH_V1 payload length, decryption failed?'
- The error seems to be related to not being able to decrypt payloads
- Additionally, I'm getting 'No matching CHILD_SA config found for IP/IP. received DELETE for IKE_SA' on the responder side

Your Role:
- The primary task is to address and rectify the issues causing the tunnel failure
- As of now, the problem seems to be primarily on the responder side

Ideal Skills for the Job:
- Proficient in StrongSwan VPN
- Strong troubleshooting skills
- Experienced in resolving encryption-related issues
- Familiar with debugging and resolving tunnel failures

I'm using a Pre-shared key for authentication. Prior experience with StrongSwan tunnel configuration would be a plus.

The tunnel is up and ping ok but a moment ping stop and we have those errors.