I never had jumping Paros myself, but … I always covered my tanks. The best Paro-scientist I knew, Dr. Walter Foersch, founder of Paro-aquaristics, never saw jumpng Paros, but always covered his tanks, too.
On the other hand I know of some people who were surprised by some Paros in this respect; trusting in the non-jumping they left tanks uncovered, and … the fish jumed out. But besides this happens rarely only, in the cases I came across those tanks either were meant as a provisionary home only, not equipped “orderly” as Paro-tanks, or the feeding or the water values were bad.
I strongly advise you to cover all Paro-tanks although fish accustomed to a good tank with a good milieu and regular feeding hardly ever jump.