Text Message Forwarding with eSIM?

My eSIM is now with AT&T and my physical sim is with an Australian carrier (Telstra). Since configuring my iPhone this way, text messages (green SMS, not iMessage) sent to my physical sim Australian carrier line are no longer forwarded to my other devices signed into iCloud.

Anyone know if this is by design or a bug which will hopefully be fixed in a future update?

As it stands now, in order for me to send and receive normal SMS text messages from my physical sim Australian carrier line, I am restricted to doing so from my iPhone. Cannot do this from my MacBook or iPad like I can when a green SMS text message arrives on my eSIM AT&T line.

Hope all this makes sense.

I used to have a second iPhone for my Australian number so when texts would arrive on the line, they would be auto forwarded to all my devices signed into iCloud which was a great feature. Being able to respond to texts from my other devices.

I live in the US.