Hi vyanezf, thanks for bringing this to our attention.  We think we've found the culprit: if the input is hot enough, it is currently possible for a little bit of that negative polarity signal to leak into the envelope to rate feed, causing the lag that you are experiencing.  This will be more noticeable if your input is steady (e.g., a synth pad).  

We have a fix for this issue that should come out soon but we want to test it a little further before we release it.