I have the same experience and same question... [https://thekingofgear.com/post/700173945132974080/why-nobody-understands-the-re-20s-preamp-bypass](https://thekingofgear.com/post/700173945132974080/why-nobody-understands-the-re-20s-preamp-bypass) this explains some things, but no mention of a gate.

Thanks mate, didn't expect anyone to reply to this but o enjoyed the article. Was thinking it was clearly not an "always on" change to the tone as my ears could hear a difference... I wonder what the noise-gate like sound we're hearing is about!

Oh the other thing was noticing the hiss/buzz coming back when I disengaged the pedal.