Multiple audio tracks but only playing out L channel

[patricks48555507]

So perplexed.  I've been working on a project, already synched up several timelines but suddenly only the one channel will play out.  It's not the headphones, not the interface or sequence settings, no new version has been updated, tried earlier fixes of creating new timelines but nothing is having any effect. 

Working on a MacPro PP v 22.0

Thank you in advance for any thoughts / suggestions!

[patricks48555507]

Since posting, I've tried the following ideas, installed and opened in 23.0, moved project to a new computer, created new project and brought in footage and timelines, deleted cache of course - all with no change in initial problem.  I keep thinking it has to be a project, playback or timeline setting but nothing changes it and it didn't change since this problem appeared this morning.  Other projects play normally.  Thanks in advance for any guidence on this. 

[Averdahl]

Thanks in advance for any guidence on this. 

By @patricks48555507

As a test, what happens if you create a brand new project and import a couple of the clips you use and place them on a timeline, do they play back as expected or only in the left as well?

[Baffy19]

Display the sequence settings of the Audio tab in the screenshot and provide a screenshot of the Audio Channel, where the channels are routed.