If wiggling the cable causes your pedal's power to cut out, it could be do to a damaged power jack, corrosion, or dirt on the power jack contacts.
The jack has a spring that pushes up on the outside of the power plug barrel connector so that the inside of the power connector makes contact with the pin. You should be able to see the spring by looking in the power jack.
Corrosion, dust, and exposure to humid conditions can make the jack dirty. You can clean it using a Gum Proxabrush go-between or similar interdental brush (a small brush that people wearing braces use to clean hard-to-reach parts of their teeth).
Turn off an unplug your pedal. Dip the brush in 70% or higher isopropyl alcohol. Tap the brush on the mouth of the bottle so that it is moist, but not dripping wet. Insert the brush into the power jack and clean the top side of the flat metal spring. Also clean the center pin. Move the brush in, out, and in circles. Repeat the process a few times with fresh isopropyl alcohol.
You can also clean the inside and outside of the power cable barrel connector (with power disconnected).
Wait at least an hour to let the power jack dry out, then reconnect power and see if the problem is improved. If not, contact us to arrange to have your pedal repaired.