I have done many different tests (including the one from here) and also looked into how each function works to determine what type I really was. The tests can be pretty much inaccurate and you can even perceive yourself differently than you truly are (or how others perceive you). A lot of the tests are based on your lifestyle rather than your personality, and the traits you had as a kid make it clear what your dominant function is. Whatever you're bad at would be your inferior, and whatever you react like when in a bad mood / stressed out determines your shadow functions, such as demon or trickster.
Ironically my
first ever result was ISTP, which is actually very close to what I am (given how these inaccurate tests with sliders work) since I'm INTP. One letter being different makes a massive difference though, and in these tests you could be off by only 1% and get an extremely incorrect result, because they don't work in actual cognitive functions, hence why they're not very accurate.
I used to get ISFP here in 2018 when I was technically not in a great mindset (it's also clear I didn't understand anything about MBTI back then

). The reason is because I used to think "I don't think about the future I just want to enjoy myself now", which is typical Se (xSxP). That's not how I work in reality though, and I'm always worried about what's coming next (which is why I can be anxious about things at times too). I used to just do that to try avoid being depressed, not thinking about later / the future = not feeling sad / stressed. I also use a lot of past preferences to learn thing (Si, not Se), though I don't think my Si is as high as my Ti as to be xSxJ.
The tests can give you very different results depending on your current lifestyle, hence why they're inaccurate. Your type isn't supposed to keep changing, it's how your brain functions.
There is info
here on how the function stacks actually work if anyone is interested.