MAS 7.4.1 on Sierra 10.12

I have managed to get VS to connect to my server via a SSH tunnel. This, however, is a tenuous connection, as the following happens each time I start VS:

I have a connection bookmark with all the necessary servers and passwords set, as well as the ssh private key file to use with the connection. I have verified the credentials numerous times inside and outside VS (ie via terminal and other db management software packages) -- the credentials are correct.

At app startup, the SSH tunnel fails to connect with 'Authentication by public key failed!'. Dismissing this dialog brings up the connection properties for the failed bookmark. At this point. I can cancel that dialog and continuously try to connect with the book mark, as-is -- same failed result each time. However, if when the connection properties dialog comes up, I reselct the same private-key file already pointed to in the dialog, the connection goes through just fine.

the problem is not with the information, it is that the bookmark does not seem to properly connect back to the designated private key file as set. The path value before and after refreshing the key file is exactly the same. Something is happening behind the scenes to that the 'stored' value is treated differently than a 'fresh-set' value.

Thanks