If the unit sends the charge as an intermittent pile, you may have tested it between pulses. . . The grabbed it at exactly the right (or wrong) timeMany, many years ago I installed a half mile of electric fence. Temporary until I had time for permanent barbed wire. I had a little, cheep-O electric fence tester. It seemed to indicate - no voltage.
So.....out of pure frustration I grabbed the wire. REALLY BIG MISTAKE. It didn't knock me down on my butt - however it was close. The @#$% tester went in the garbage.
Some people learn by reading.Will Rogers had a good line about that…