Hello!
Channels are not muted and sequenced notes light up, but nothing heard. I can play all channels through my midi controller (Novation sl mk 2) and record into the sequencer. It was working just fine a couple of days ago, but I either made a tweak to the DT or the controller and I can’t figure out what it was. I was attempting to output midi via 5 pin, but was getting feedback loop and tried USB output which prevented the loopback, but still not hearing midi sequences. I’ve tried many adjustments to the midi config settings and I’m ready to tear my hair out. Or perhaps you all could save me from that. Help! 
Hey, your sequence that you’re trying to play, it’s set on a midi track, correct? On the Midi SRC page, what channel do you have set for the CHAN parameter? How are you monitoring audio and where from? What is the midi device you’re trying to control with digitakt’s sequencer?
Can you hear digitakt’s audio when you play the audio tracks with the midi keyboard controller, just not the sequence from midi tracks?
The digitakt shouldn’t be getting feedback unless you have the digitakt midi out plugged into another device which then plugs directly into your SL MK2 and then back into digitakt, the feedback loop is a result of digitakt sending and then receiving it’s own midi output.
So currently, you’re using USB midi? If you can give more details about the general setup and any software you’re using if this is running through a computer, it will be easier to help.