Using "Adobe Form Submit” getting a dialog box error with error “An error occurred during the submit process. The server has an invalid SSL certificate"

Please note, this works fine in many environments/networks but there are a few that are experiencing this error consistently.  Here is other information about this error:

1)  We seem to only getting this error in environments where the SSL is internal (not created publicly).  If the SSL is public it seems to work without issue.

2)  We have tried to add the certificate directly to adobe DC's trusted certs with no luck.

3)  This error occurs when we launch Adobe DC in it’s own window; however, if we enable the Adobe IE plugin (in manage add-ins) and open up the form in the IE browser window we do not get this error and it submits without issue.

4)  By all accounts, the cert seems trusted and it is the anchor....

Thanks in advance for guidance about what Adobe does not like about the SSL cert!