I am one of them.
And it should be remembered that Jungian Cognitive Function -and- MBTI both are symbols talking about your psychological behaviors.\
And you should remember that the nature of most online tests are questions-- which in its coding, often leave little subtlety and variety.
So personally speaking, you need to look at your own thought patterns during each seasons.
Are there differences? In what ways?
For me, when I'm depressed my thought pattern circled around me. My flaws, my wants, my needs, my perspectives, me me me.
And I tend to try to protect myself, better myself, avoid people from harming me; focusing on my own internal values and what is right and wrong.
The function working is actually Ni and Fe (and some amount of Ti), but the way it's working makes it somewhat Fi-like (in a negative, stereotypical way).
Therefore when I'm testing and answering questions, It's likely I'm rating things corresponding to Fi higher than usual, giving more Fi to my score.
But this is me, and I don't know about you.