Network Definition Availability Groups not working in Firewall Rules

I add a few of my workstations as Hosts in Network Definitions.
I add these Hosts to an Availability Group in Network Definitions.
I use this Availability Group as the Source in a Firewall Rule.
The rule only works for the Host at the top of the list in this Availability Group and none of the other members.
Is this the wrong way to apply a Firewall Rule to multiple workstations?