Cannot unfreeze tracks

At the suggestion of several YT gurus, I froze the tracks in a project that was overloading the CPU. Now when I open the project to finish editing, all tracks show as locked, yet they do not respond to the Edit>Freeze/Unfreeze or to the Shift+Command+U commands. I am stuck. A little help?

TIA David
Mac Monterey, Cubase Pro 12


Could you attach a screenshot, please? Maybe we will see what’s going on.