In my experience, A-T is and acts like any other VST or TDM effect. There are both mono and stereo versions though, using the wrong one will cause anomalies… though it seems unlikely you'd pass audio with just no effect especially if the meters indicate pitch correction happening.
Dumb question #1: Are you sure you don't have the bypass engaged?
Dumb question #2: Is the "correct pitch" button engaged in the A-T window?
Dumb question #3: Are you sure you're monitoring the output and not the input?
I said these were dumb questions… before you get to feeling insulted, I'll admit I've been at this shit for 25+ years and I still miss the obvious once in a while…
Last, I have the manual BUT there's a separate "read me" that came with each format. Still doubtful though, that you could have some kind of setup fail and yet get signal as far along as you are.