Interesting Yvette....can't say I've had that issue yet....but I usually cook with our own beef/lamb, so I know it's quality & has been hung for a good period of time....not like the supermarkets. That does impact on tenderness.
I do know that you can overcook in the PC, as well as undercooking....so maybe Check the doneness a couple of minutes earlier than recipe states, as you can easily add extra time to cooking if needed.
I guess it all depends on the meat.
Yesterday I forgot to defrost meat for dinner, so I grabbed a peppered sirloin roast & a spiced roadt from aldi & cooked in PC.
I seared, than it suggested to cook in basket with 200ml water (I cooked for 40 mins. for the 2 of them)
It turned out great
Kids only like eating meat cooked in the PC (Lazy chewers I'm guessing)....hubby slowly coming around to it