@Solla-topee thanks for the reply. Yes, you're right about the dimmer model and yes it is a 2way switch. I initially tried to connect two smart dimmers but in the photo you can see that I've tried...

I've installed a couple of these switches in my house, but ran into a problem with one... There are 4 switches in the box with the line load wires all connected together. I ran a wire from that...