This can be caused by the stylus itself in rare cases the metal piece inside the stylus may not be fully tight. 

First remove the stylus from the tablet:

Second unscrew the tip from the rest of the stylus:

Third unscrew and remove inner metal piece from tip of stylus:

Lastly screw all three pieces back together in the reverse order.  Make sure that each piece is only finger tight.

After you have done this place the stylus back in the tablet you will see this:

Then remove the stylus and you should see this now to confirm it is working: