I am also having this issue. I just bought the tablet (SM-T217S) and updated to 4.4.2. I flashed TWRP with Odin and then flashed armeabi universal root through TWRP as per these
instructions. I see SuperSU in my apps but it crashes on start. Apps that require root don't work also.
I need root so I am willing to downgrade Android for it but I would love to have root on the stock 4.4.2.
EDIT: Found the solution. Follow the instructions found here
(same as above), then flash the SuperSU update attached here