Bad;

That would seem to be the next thing to check...before replacing, remove from distrib and check outer and inner surfaces for contamination and/or discharge paths...clean with detergent, dry reassemble and try again.

Occasional cleaning of dist cap is good practice. The central brush which rubs on the rotor does get slowly worn away, and the carbon dust which it makes, gets all over inside of cap, promotes condensation, and can lead to discharge paths other than out the individual cylinder wires.

Good hunting