Some CM15A devices don't respond to ON

I bought from HS a new CM15A to replace my failing CM11 device.

I've spent the last few weeks trying to get this interface to work reliably.
I've solved almost all of the issues except one:

I'm getting the following entry in the log when I try to turn ON a CM15A device from the HS web interface (or HS Touch) for 'SOME' of my newly added CM15 / devices

Jul-29 5:02:24 PM CM15A DEBUG Received CM15 Address:B6, Command:extcode
Jul-29 5:02:20 PM CM15A DEBUG Received CM15 Address:B1, Command:on

B1 works great
B6 will not respond to ON (it Will respond to Bright, Diim, Off etc..) just not ON

Some devices work great, some will not turn on, and generate that entry.
Those devices that will not turn on WILL turn OFF and DIM on (to full even) but will not respond to a "ON" command from HomeSeer

Thoughts?