I have a speaker group called Party. I cannot cast from any audio source
to the entire group. Even if I go to the home app and select the group,
I cannot connect to it, only one speaker.
My mesh does have band steering functionality, but I have confirmed that
all speakers are on my 5GHZ band. Additionally, this speaker group used
to work. The functionality only recent broke.
The devices in the group were two nest minis, and one Google home mini.
I have since deleted the group since it didn't work Yes I have a dual
band home mesh by TP link.