That's probably because you confused Vim and Kakoune key bindings.
Kakoune
- n: next match
- alt+n: previous match
- shift+movement: extend selection by movement
Vim
- n: next
- shift+N: previous match
So if you press shift+N as you are used from vim, you start adding a lot of selections instead of going to previous match. I believe this difference is the most confusing for people who switch from Vim to Kakoune.
Kakoune
- n: next match
- alt+n: previous match
- shift+movement: extend selection by movement
Vim
- n: next
- shift+N: previous match
So if you press shift+N as you are used from vim, you start adding a lot of selections instead of going to previous match. I believe this difference is the most confusing for people who switch from Vim to Kakoune.