I've been installing Meross MSS550 smart 3-way switches at my house and most of them have been a breeze. However, I have an atypical setup that I have not been able to figure out. I've tried many wiring configurations, but I either get no power to the switch, power to the switch but the lights always on/off or power to the switch when the other 3-way is toggled in the correct direction.
My wiring configuration is this:
The switch's wiring diagram is this:
This post seems to talk about my exact configuration, but I can't decipher exactly what he is doing other than connecting the line to common on the switch. I've ended up with various different problems. Lights always on, but no power to the smart switch... lights always off and smart switch has power but does nothing... etc...
EDIT Here is a picture of the switch as it was wired and working (the switch I am trying to replace). I think represents the left switch in the first diagram I posted. However, as mentioned in the comments, I am not a master electrician, so happy for someone to correct any misunderstanding I have.