Ok I got it working. You as a main family member have to sign out on your iPhone from App Store and sign back in. Then you will get prompt saying your family members are part of music share (Apple Music)
Just tried that - no such prompt here.
I would've hoped they were already exceedingly aware of this problem and frantically working on a solution… Sounds like that's not the case. Thanks for calling!Spoke with Apple this morning. Advisor then senior advisor, the senior advisor then escalating to the "iTunes" department on the back-end, no resolution.
The senior advisor is now escalating to the "engineering" department and is supposed to get back to me.