actually I noticed something else is not right!
I started debugging and removing stuff one by one. I removed ardour and guitarix. right now just trying to get qjack working. I should be able to hear raw guitar sound on my headphones just with qjack, correct? but that itself is not working...
when I check pavucontrol -> input devices, the scarlett is there, and when I strum a string on the guitar, the bar goes up -> the signal is being transported.
so from my understanding I need to fix qjack as it is the main culprit right now.