Found this issue of dropped samples - leading to clicks - on Audition recordings at Studio with the Audiogram interface. And maybe even with the Presonus too. The workaround was to record using Nuendo. S emailed with the solution as implemented by PB -
The clicks problem recurred and PB has once again reset the Preferences/Audition folder.
Now it is fine.
Finder/Go/Option key/Library/Pref/Audition -->Trash