Drug test question - 10 panel accuracy

So just for shits and giggles I bought a ten panel drug test off of amazon to test myself with knowing I would not pass the THC section. Well to my surprised I passed the THC section but did not pass the cocaine panel. Are these thing that inaccurate? I haven't done any coke in years. They're so cheap about thought about getting a couple more and seeing what the results are. It worries me that these things could be this inaccurate.

They've always been pretty accurate for me..... not sure if anything causes false positives for coke. or if you just bought a really cheap one or what

Ten pannel can reffer to many different styles of tests

but Im guessing you got a dip-stick style test ?? If so then in my experiance their inaccurate , I would wrongfully fail about 1 out of 10 . Many of the tests offer lab verification if failed by mailing away check the box / instructions

Some of the individual pannels are known to be alot less accurate than others , opiates and amphmetimens are 2 becouse of many OTC products that are structuraly simmilar and or things like poppy seed that contain trace amounts. Alchool is 1 as well many people have enouth alchool producing bacteria in the right spot in their gut to produce enouth to fail tests. 1 person was just found to be permently drunk . As well as the mouthwash vannila extract, cough syrup ect. ect.