Git traped?

 I've a file in a Git control project that I've do some local change, and don't want it to be overwrite.

so I use

$ git update-index --skip-worktree <file-list>

to avoid the over write

but strange thing happen today when I'm trying to checkout another branch, Git ask me to commit / stash local change, but when I stash local change

git> No local change to save

but when I checkout

git > please commit your changes or stash them before you switch branches

my Git version is 2.30.2

so I can only 

$ git update-index --no-skip-worktree <file-list>

then 

$ git stash

$ git checkout