first audio track in session randomly loses it's voice or something?

[Inglesworth]

Current system:
Pro Tools HD 12.6
OS 10.12.1

I have experienced this on many different combinations of pt versions and os versions on many different computers for several years.

Sometimes, the top audio track in my session stops playing back. It is active, it says it has an active voice, it has an active output, etc. It worked 30 seconds ago, and I hit play and something is missing... Oh, the first track isn't playing anything. The meter moves on it, everything looks fine, visually.

For a long time, this would happen and the fix was to save and close my session and re-open it and everything is fine. One day it kept happening, and I just created a new audio track and put it first in my session and just didn't use it. This seemed to work as well. Once I discovered that, I could just make a new track and there is no need to save, close and re-open.

But I just upgraded to a new computer with a brand new version of pro tools. This bug that I have been experienced since the pt8 days can't still be around, can it? Sure enough... It is!

Has anyone else ever experienced this? Is there a way to fix it?