I'm trying to use a Matter 3gang switch on a C-7 model.
By the way, if you bring the 3-gang switch of Tuya, ST to Hubitat, only 1 will work or not.
I did the test with the Moes Matter switch.
How can I solve the problem?
It will likely require a custom driver.
This is totally a wild guess, but it looks like a single matter device with 3 buttons that controls 3 different relays. The default matter switch driver probably only connects to the first endpoint/relay. You likely need a custom driver that can talk to the additional endpoints for the other two relays.
I solved it using kkosev's driver.
I applied the device type as Matter Advanced Bridge as Kkosev suggested.
Can you test also the HE inbuilt 'Generic Matter Multi-Endpoint Switch' driver?
It should be working also IMO.
This does not work.
I think HE should officially solve this part.
I never even thought I could solve this with your driver.
As expected, you are HE's treasure.
I changed it to 'General Matter Multi-Endpoint Switch' today and conducted the test.
It works well.
The problem is that four spheres can't be created,
It seems to work after 4 pitches are created using your driver.