CQ18T Headphone A and B only left ear?

Very strange thing here. I have Aux 1 and 2 linked stereo

I have Headphone A and B sources mapped to my Aux 1/Aux 2 stereo link

When I plug a stereo cable into my headphone amp I’m only hearing things in left ear. If I pan, for example, piano hard right it disappears…sometimes can FAINTLY hear it from Heasphone Out A. Nothing from B

If I plug a pair of headphones directly into headphone jack A (taking headphone amp out of the equation) I still have same result

It USED to work fine. Any idea what I’m missing here? I’ve factory reset same results

If I plug a mono a/b to stereo directly into Aux 1 and Aux 2 works fine

Really like headphone jacks though for reasons not worth getting into

Any tips for debugging?

Thanks

Oddly enough I switched the source on the headphone to MainLR and it worked fine

I then switched my source back to my stereo link aux 1 and 2 and everything started working

Sometimes you just have to shrug and move on. No idea what happened but it works again