How come the Live button actually creates a slight delay?

[feedingear]

I'd play with adjusting your buffer. The other key to getting arps to sync is to start playback on beat 1 of any bar using your quantise. being slightly out will totally fuck it. that said, they can still drop out and flip out if you repeatedly stop and start sections while mixing/producing, and the only workaround I have found is zen like patience.

that or freezing the arps during intensive microediting/mixing work.

[namnibor]

You also may need to go into your Focusrite Scarlett Mix Control and make a few tweaks to settings and once you get it where you like it, SAVE it as one of your saved set-ups that Scarlett Mix Control allows...and of course saved in your DAW settings. I have the Scarlett 18i20 and using Reaper.