Phonak Lumity suddenly not streaming two devices

My Phonak L70 HA used to stream effortlessly from either my MacBook Pro or my iPhone 12 without having to turn BT off of either device. Now I must turn off the BT on my MacBook, or there is no. sound (for example on YouTube or Spotify). Going the other direction seems fine: Whether or not BT is connected to my iPhone, I can stream Netflix and YouTube on my MacBook. I recently upgraded to IOS 17.1.1 on the iPhone, but I don’t recall if the problem started with that. Additionally, I am only getting about 11 hours with my HA before I get the “chimes of death.” And that’s w/out a lot of streaming. I’ve restarted, re-paired all devices, and the problem remains. Phonak Tech support said they’re not meant to stream two devices, but I know they are, and did previously. What to do?