.................... The Fenix TK21,PD32UE & PD31LE all come on when I tighten the tail cap regardless if the cap is turned on or off...............QUOTE]
I don't see how the light could come on if the tail cap switch is off. Can you post a picture of the battery at both ends? Also if you have a voltmeter you probably could run down the problem on the battery. Maybe the wrapper on the batteries isn't completley isolating the ground connection up near the protection circuit and somehow it's making contact with the inside wall of the flashlight. If you look inside the flashlight you will see a spring or bump where the battery's positive terminal makes contact. Around the perimiter of this PCB disc is a sort of gold platting that is the ground connection to the chassis of the flashlight. It just seems from your description that the battery's ground connection must be touching that. Because I can't see how it would at the tail end. Batteries without the protection circuit just have a (+) and a (-) end. In order for the protection circuit to work, they run a strip of conductive material down the full length of the battery to this protection circuit so that the circuit will have a ground reference. My guess is that somehow this isn't insulated properly up near the top of the battery.
By the way those "Panasonic" protected 18650 cells may be Panasonic cells inside, but when they modify it, it really should be a new name and part number and the only thing "Panasonic" about it at that point is the raw cell that they started with. From the pictures I could see at Fasttech, I think you can see a copper strip running down the full length of the battery with Kapton tape over it to insulate it. I think that strip is touching the flashlights ground path and bypassing the tail switch.
Sorry to here about your problems. The old saying "you get what you pay for might be true here" Still might be able to find the issue with a voltmeter and apply your own tape where the exposure is. I'm mostly guessing at this point as to what your problem might be.