Phonak Marvels and Bluetooth... what would you do?

Ah, i know now what you mean.
No, that is not the problem.
BTW: I edit my Phonaks by myself with Phonak Target.

You have three choices how to set up the TV connector in Target software. One automatic and two manual. My wife likes hers in automatic but I like mine in manual with a beep.

Same with Oticon. Both work well.