Suddenly, all Track names & symbols added to a file are lost when saving , & when re-opening file, all blank again.  Very annoying - didn't used to do this.
 
Also, why does Velocity not remain shown as set, instead of having to save & re-open file to see levels on Events view?

Which version of sonar ?
Sounds similar to demo mode.
Your issue seems to be system specific. not normal.
 

Using Sonar X1 LE, also used Sonar X3 Producer - same problem, with Windows 10.  It doesn't seem to do it with all Midi files, but recently has started losing all Track Names, even widgets on saving, & worst of all, now even losing Instrument Name in Track View & having to open Events List to see the instrument.  Can't seem to find any control, but obviously must have switched something off accidentally?

I cant really think of anything that would forget to save track names or the widget order in a project.
As long as that project is saved it should keep those all settings.
 
Possibly a corrupt project. wish I could help more, I just don't even know where to start.
Was the Sonar X3 a demo version ?

I agree with Chuck, sounds like a corrupted project.  As a test, try copying all clips to a new project and if you're using a project template, don't use that template for the new project you copy clips to, in case the corruption is within the template.
 
 

Could it have something to do with a graphics issue? I don't know, just throwing it out there.