After countless attempts to find a solution and coming up with nothing, I've arrived at the conclusion Voxal running in Safe Mode is the reason it doesn't apply any audio effects.
There's just one problem: it doesn't STOP going into Safe Mode. I go into options, make sure the box saying 'run in safe mode' is unticked, restart the software, and it's back in Safe Mode. I try it again, only this time, I restart my computer. It still goes into Safe Mode. I haven't the faintest idea exactly what's keeping it stuck in Safe Mode.