Good to see you back here. I was thinking look carefully at all your test results. Your results maybe within the ranges but are they almost in the middle of the ranges or at either end. See what is at either end and deal with those potential issues. Something is going on... find out what it is and sort it.
If your doc doesn't 'like' doing NK cells then go to one who will do the tests for you. Not sure where you are but ask here where a doc is that will do the testing for you. Good luck, best, THK