I need advice on what is the best thing to rely on for typing: test results, the functions, or stereotypes like " the people I met that I think were this type all had this in common"

I recently took a socionics test for the first time and got a result of LSI. I had not read any of the descriptions of the types at that time but since I think of myself as more L than E, more S than N, and I relate a lot more to the characteristics that are used to describe rationals vs irrationals the answer made sense to me.

The summary given before they described the functions had some parts where I agreed and some parts where I wasn't sure if that was an accurate description of me. When I started reading about the functions There were some parts of Ti as a leading function where I could wholeheartedly agree but some parts where it didn't sound like me. I agreed even less when it came to Se as creative and Fi as role. Ne as my vulnerable function doesn't seem to ring very true. Fe as my suggestive function doesn't seem correct at all. When I'm in large groups of people I tend to find a like minded person and talk in the corner and if there is no one to fit that criteria I would rather sit a distance away and observe but not participate. In the past when I've been given the choice to either take part in the group activity or leave, I have chosen leaving every time.

I walked away thinking that the test result was probably incorrect. I took several other tests at various sites and the all gave me a result of LSI. I finally decided to read all the other type descriptions to see if even with the things I disagreed with it was the one that described me best. It was then that I read about the quadras and that LSIs were betas. Betas seemed to be the quadra I was least likely to be. I read the descriptions of decisive/judicious, merry/serious, and democratic/aristocratic and the descriptions of Judicious, serious, and democratic seem to describe me most. It is the complete opposite of beta, but at the same time according to the 4 quadra system that combination shouldn't exist.

After reading all of the types and their functions the only one where I could agree with all 8 functions was SLI. I agreed most strongly with Fe as vulnerable, Fi as mobilizing, Se as ignoring, and Ti as demonstrative. But I agreed with most of what it said about all the other functions. LSI wasn't even the type I felt described me second best: that went to ILI.

I was trying to figure out why if the functions seem to indicate I'm and SLI, the tests always tell me that I am a LSI. Am I a LSI that is reading/interpreting the functions wrong? Am I an SLI who thinks I'm more rational than I am? Are either of these occurrences explained with specific subtypes?

I started searching for LSI/SLI differences and clarifications and what I found were message boards where people were describing SLI and LSI not on functions but on their experiences with those people in real life. Half of the generalizations seemed to contradict my understanding of their respective function orders. And for every stereotype there were some people saying it was correct and several people saying they have the two types switched. My attempt to clarify things by just reading what other people discussed just made the issue more cloudy for me.

Am I interpreting the functions wrong? Or are people just assuming people are a certain type and making generalizations while ignoring whether or not it contradicts function order?

Any clarification would be appreciated.

If it helps, I have taken the MBTI on several sites and have gotten ISTJ on it every time. I think it describes very accurately what type of person I am at work, but does very little to describe me when I am not.