How to test SSL cert from CA?

Have a client using a commercial application. For a year plus we had
been using a local self signed certificate without issues. As of a few
weeks ago a change/update to the program is making it complain about the
self signed cert.

I bought a SSL cert and installed it, but the program is still having
the issue.

Anyone knows of a way to test the SSL connection such that it validates
against the CA? Preferably an open source application. Connecting
through psql works fine on SSL with what I have setup, but the
application, xtuple, seems to still be having the issue.

The client already wrote to the application support department, but
still waiting for an answer from them.

If I had a way to at least reproduce the error I could more easily track
down what I am missing.

Any suggestions?