@jrockland I had the same problem therefor I installed 3.1.1 fw package on both, hc6 and on hc3. After this the update package 3.2 did properly updated both boards.
@JayT : Problem resolved, we just swapped the internal cables (to make sure it's 1-1 connection). i.e. CANH to CANH. The LED blinked right on power up in sync with MB6HC. This thread can be closed. thanks.
Hello, lately I've been asking the same question, did you manage to figure out a solution?
I got 16 heated beds and am about to figure out a way how to control them nicely
Perhaps best to start a new thread with your specifics. What is your use case, hardware, etc.