NRF.setScan() stops working

I mean that after setState() is called, NRF.setScan will stop scanning. Actually I check

d.manufacturerData[0]

so setState() is not called if there is no change in there, and since I change it manually, I do after some seconds, so don't think that's the problem. If for example I put these:

function setState() {
print("working");
}

then it works, scanning will continue normally. Sorry if what I'm saying doesn't make sense, I can post all the code if needed. Thanks.