Connection Issue

Dear experts,

may we seek your inputs regarding the current connectivity issue we are encountering right now?

Our partner is sending to us via normal HTTPS post, but they are encountering error,

Logs:

A message sent to adapter "HTTP" on send port "TOG_Oasis_Hubwoo_Invoice_HTTP" with URI "https://connect.company.com:443/invoke/TRSimpleAgent.Process:receive" is suspended.

Error details: The underlying connection was closed: An unexpected error occurred on a send.

MessageId: {702E8EBE-B4C2-46F0-9239-4D526DCE80BC}

InstanceID: {5B3A30EB-303A-4ABE-9B4A-E8AA8CD4676C}

Do you have any helpful links for this error?

Thanks!