Wiring Help: Shelly 2.5 + 4-way/3-way Switch

Hoping I might find some electrical wiring + Shelly gurus on this forum.

I’ve wired a number of Zooz/GE/Innovelli switches (including GE dummy switch for 3-way) in the past but the Shelly seems much more complicated for some reason. The included wiring diagram is unclear to me.

Here’s what I’m trying to do: I have a lanai with lights and a paddle-fan. The lights are controlled via 3 switches (4-way) in 3 different rooms and the fan is controlled by 2* switches (3-way). I bought a Shelly 2.5 in hopes to place it one of the 2-gang boxes to control both.

  • At some point one of the switches stopped working (Living Room). However, looking at both switches, I don’t see a traveler wire so I’m stumped as to how it worked. Or maybe I’m going crazy and it never worked?

Here is my rough wiring diagram:

In the Living Room, I have one switch labeled “Fan?”; this is the switch outlined above that I BELIEVE use to control the Fan as well but based on the wiring, I don’t see how this could have worked in a 3-way fashion.

I’d love to fix that switch however my main question is how can wire up the Shelly 2.5 to control both Lights + Fan? I’d imagine I need to place the Shelly in the Dining Room 2-Gang box as it’s the one with constant power.

I’ve watched Dr.Zs YouTube videos on this but it’s still not clear to me.

P.S.: Does anyone know of a good diagraming tool to illustrate the above better?

No offense but that drawing is pretty useless because it doesn’t show the interconnections between the cables going between the boxes.(which romex bundles labeled 1, or 2, or 3 are connected together, etc.?) - unless I’m missing something…

but here is a decent wiring diagram and explanation on how a 4-way circuit works.

Maybe you can look at that drawing as an example and come up with a better drawing of your existing wiring.

And yes the Shelly will need to be in the box with a neutral wire in it (dining room from the drawing above).