I am having the same problem with 9.5. It was working fine in 9.0.30. I was running a plugin on insert one then my external fx on insert 2. I though there was an issue with the version of plugin I had on insert 1. Seems to be 9.5 instead. Hope they come out with a update for this soon. I really like having 16 inserts in cubase and would rather use 9.5 then 9.
EDIT
Yeah, it is still sort of weird in 32bit. I may have to use Cubase 9 until there is an update.