I recorded a mono signal to Sonar which may or may not have rendered it stereo. When Sonar renders them stereo I convert them to mono. This one plays left side heavy when pan centered. I want it to be balanced. Converted it to stereo and back to mono. Still left side heavy.
 
The clip is OK so it must be something with the track settings?
 
Only way I see to fix it is to create a new audio track and drag the clip to it.

Hi. Is it the same in headphones? I cannot say I have seen this behavior before.
All the best.

Any FX on that track Soens ? Could be a stereo plug in forcing the signal toward one side more than the other.

A stereo track converted to mono is as mono as a mono track recorded in mono. Nothing special about it. However, if SONAR recorded it stereo initially, it's possible the track interleave is still set to Stereo, so check that in the Inspector panel.
 
As Chuck notes, stereo plugins can mess with your panning when inserted into a mono track. Internally, SONAR will convert the data stream to stereo to accommodate the stereo effect. If the plugin doesn't know how to handle a mono source properly (many don't), it may very well shift the image. Take out any plugins and see if your left bias persists. 
 
 

Also, offset mode, the joy and bane of the Sonar user.

I checked the track interleave and it's mono. The bus interleave is stereo as it should be. Changing the bus interleave to mono solves the track meter issue but ruins the stereo output.
 
I have a Sonitus EQ plugin on the track but there's no stereo controls on it. Even so, when I turned it OFF the meters behaved properly. Turned it back ON and it still behaves properly. After fooling with every control and setting available I have to blame the Sonitus EQ for the meter glitch.
 
My thinking is no matter what the interleave or record setting, the clip is a mono clip and the meter should display it that way unless the pan is off center.
 
Thanks for helping out guys!

I have seen that in the past when opening an older sonar file.  I would just clone the track itself without any automation, just the events, forfeiting any work I have done.  

Did you check Offset Mode as suggested by Sanderxpander? Every time something like this happens to me it turns out that the pan (volume, etc.) has been altered in OM.

Oddly when I opened the project again offset was ON (hmmm), but before I turned it off I found the meters were behaving correctly. This is project version 28 so I went back to version 4 saved in July and found that's where I turned it on. So maybe it's to blame.
 
For now all's good.