What's up with khan academy

So I took 2 practice tests on khan academy the first one I got a 1260 however on the second one in got more correct but dropped 30 points why is that

Best guess is that one test was harder than the other one so the equating (sort of like the curve for the test based on its difficulty) was different for each test. In the easier test, you could get more questions correct, but it was an easier test, so there is less “equating.”

Another reason could be if you missed a bunch on reading the first one but a bunch on math on the second one. Even though the amount of questions missed may be the same, math is in its own category and thus will have a bigger impact if you miss a question.

Same thing happened to my D yesterday. She was working on the Math section. The second test she took, she got fewer answers correct but her score was 50 points higher.