Mendelson AS2 server not creating same MIC as openssl

I am trying to prove that my mendelson as2 server is creating the correct message identity and believe it is not. If I take any of the payloads in the sent directory and run it thorugh openssl I am getting totally different results to the required Message Integrrity Code (MIC).

e.g. from the console.

The Message Integrity Code (MIC) does not match the sent AS2 message (required: jbIuEUjcb8YoGmRTnyP++Iw00Eo=, sha1, returned: Mgr/0EAYzwELwdjrNK0I3m9MNvo=, sha1).

But generating the MIC using openssl gives the returned value, not what mendelson is expecting.

"c:\program files\git\usr\bin\openssl.exe" dgst -sha1 -binary mendelson_opensource_AS2.txt | "c:\program files\git\usr\bin\openssl.exe" enc -base64

gives me

Is my openssl command wrong? Is there a bug in opensll or mendelson digest generation?