Is your unit in DSP bypass mode? I haven’t tried the pre/post routing, but I know that if you use the true bypass mode the relays can cause audble clicks sometimes as they don’t switch at zero crossings.
I don’t have access to my H9 right now but my delay and reverb trails spill over when i hit bypass, so i’m assuming i’m set up for DSP bypass. last i knew, your tails get cut off when using true bypass.