I am completely unsure of what 'layla' is, so forgive me if I miss the mark.
The basic routing assignments for a soft synth and associated audio track should be:
For the audio track (or tracks if stereo)
Input: Should be set to the output of the soft synth
Output: Should be to Master, or to a Bus (which then routes to Master)
For the Midi track:
Input: Set to omni in most cases
Output: Set to the soft synth you want this track to trigger
For drums, I record them all on midi channel 10, and have separate audio tracks for each drum kit piece.
I use dedicated midi channels for each soft synth instrument, whether that is multiple separate instances of synths or multiple instruments loaded in 1 synth (like TTS-1 or Kontakt).
This is certainly not required - I do it so that if I ever create midi files of songs that they reduce the amount of prep work needed for someone else to open and use my midi file. I download and use a lot of midi files that kind folks have put together, and I owe it back to that community to setup my midi files to be as easy to use as I can.
Sorry I drifted into midi channels. I meant to stop at just saying that since you referenced TTS-1, which allows multiple intruments to be loaded, that what I would recommend is a separate midi track for each loaded instrument in TTS-1, with the Midi Output Channel assignment for each of those tracks to be set to the appropriate channel number for that track's intended instrument (and labelled as such).
Bottom line - please review your track routing assignments, as compared to my examples - try adjusting yours to match my suggestions, and post back with results - OR please let me know where I goofed in my read of your post, so that I can better address your situation.
Lastly, I preserve my paragraph formatting in this forum by using Chrome. I believe Firefox has issues - but I think this depends on which version of Firefox one is using. I think IE may also work, for preserving post formatting, but I am not completely sure. I just use Chrome and it works.
Bob Bone