Confusion with Matrix view row routing - get unexpected results

OBTW - I love 8.5.1 pe - now to my confusion

YES I've read the online help 
BUT
I'm still confused with the routing of rows in the matrix view

Example: My assumption is that a row can be assigned to any same (mid/audio) track - and should follow that tracks routing

In this example it's midi destined I thought, to got to a soft synth with different programs on different midi channels

Open TTS-1 and create two midi tracks to TTS-1 but routed to different channnels (say 1 and 2)
In TTS-1 set channel 1 to a piano program and channel 2 to guitar program
open matrix view and import a pattern to row one and row two
route Martix row one to TTS track 1 ( channel 1 piano program)
route Matrix row 2 to tts track 2 ( channel 2 guitar program)
Activate matrix cell row one and it goes to TTS channel 4(???)
activate matrix cell row teo and it still goes to TTS channel 4 ????

WHAT'S WITH THAT??

And if I load a second instance of TTS and apply row 2 routing to that second TTS the second instance responds on Ch 8 - 
I've checked the track properties to see if somehow that was the problem but they seem OK

Any ideas?
Thanks,
Fred