[TJ Allen]

I also don’t know anything about Drumcore (haven’t actually heard of it), but at a quick glance looking at your screenshots - if it is a VI, it is likely that placing it on an Audio Track will ‘intercept’ any audio files placed on that track. Unlike a typical insert plugin such as EQIII, which would receive and pass on any incoming audio, a VI won’t be expecting incoming audio, so won’t have an input path, and will essentially block it.

This is all completely hypothetical, so my apologies if I’m totally off the mark here, but could it be the case that the first time you are hearing the drum loop, it is some kind of preview being played by Drumcore, and you aren’t in fact hearing any audio from the actual track until you remove the Drumcore insert?