I've just upgraded to 1.8.1.
I opened an existing afpub file, which suggests preflight issues (red bell).
If I try and export then the "Preflight warnings" dialog is displayed. If I click on "Open Preflight" nothing happens; i.e. I don't see the Preflight panel.
If I double-click the red bell I don't see the Preflight panel.
Am I missing something?
I'm on Mojave 10.14.6.