git magic in contrib/bc

Not sure if it's just me, but I'm seeing a bit of git weirdness in
contrib/bc:

$ cd freebsd-src
$ git status
On branch main
Your branch is up to date with 'origin/main'.

nothing to commit, working tree clean
$ cd ..
$ cp -a freebsd-src freebsd-src-copy
$ cd freebsd-src-copy
$ git status
On branch main
Your branch is up to date with 'origin/main'.

Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git restore <file>..." to discard changes in working directory)
        modified:   contrib/bc/bc.vcxproj
        modified:   contrib/bc/bc.vcxproj.filters
        modified:   contrib/bc/bcl.vcxproj
        modified:   contrib/bc/bcl.vcxproj.filters

no changes added to commit (use "git add" and/or "git commit -a")

I can't figure what exactly changed in these files, diff (normal
command, not git diff) does not show any differences, they are not symlinks.

This happens with clean clones from git.freebsd.org,
gitrepo.freebsd.org, and github; it did not happen previously (not sure
when it started though) -- I was usually just copying the whole tree
into ~/ws/.

Any hints?