@sparkie, to check whether everything is communicating properly after startup, you can do any one of the following:

Send M409 K"boards" and look for each board in the response.

Go to DWC, start the Object Model Browser if you haven't already (it's under General -> Built-in plugins), go to the Object Model page and expand "boards". Expect to find all the boards there.

Create a List Boards macro containing the following, and run it:

while iterations < #boards echo "Board type",boards[iterations].shortName,"found at CAN address",boards[iterations].canAddress

Again, this should list all boards in the system.