Quote:
so it was hard panned left on a stereo track


If it is indeed on the left channel, do as John said and split it to 2 tracks, then look at which one has the signal, center the panning for that track, and get rid of the rest of the resulting (empty or un-needed) tracks ..

It probably behaved as expected but the new mono track was still panned left so you may not have noticed it exists.
This is expected behavior for me, as many times when I split a stereo track to 2 MONO tracks I *want* to preserve the panning (and end up with 2 MONO tracks of a stereo image) .. if you don't, then check the new resulting MONO tracks' panning settings.

Make your sound your own!
.. I do not work here, but the benefits are still awesome