Ok so im going crazy over this, I did do a search but didn't manage to figure it out.
Very simply if I create a normal bus with reverb and solo it in the default post pan mode I can hear the wet only signal. Super duper.
But then I can do the exact same thing on another track and create a new bus and it wont let me hear the wet without having to change it to pre-fader.
I really cant figure out why sometimes I can do this and sometimes I cant. I have tried playing about with different plugins on the bus, audio v midi, different projects etc but no luck.