Same experience: a few months ago I wrote both the question and the answer (I used to do that a lot for tricky things I figured out after a lot of research).
My question got closed, with bullshit reasons. I kept asking to reopen over a few months, just to see what would happen (because clearly it was a good question and a good answer). After 3 months it got voted to be reopen. Since then I got badges for "popular question" and many upvotes there.
Pretty clearly I was closed by people who did not understand the question and probably had not even realized that I had answered it myself.
My question got closed, with bullshit reasons. I kept asking to reopen over a few months, just to see what would happen (because clearly it was a good question and a good answer). After 3 months it got voted to be reopen. Since then I got badges for "popular question" and many upvotes there.
Pretty clearly I was closed by people who did not understand the question and probably had not even realized that I had answered it myself.