includeIf ignores subdirectories (possible bug)

I've noticed a strange behavior, which might be a bug.

When I'm in a subdirectory of a repo, the IncludeIf is ignored, which makes
certain tasks only possible in the root directory of the repo. e.g. commit

Here's a minimal config:

.gitconfig:

[includeIf "gitdir:~/projects/personal/"]
    path = .gitconfig-personal
[includeIf "gitdir:~/projects/work/"]
    path = .gitconfig-work
[commit]
    gpgsign = true

.gitconfig-personal:

[user]
    name = Helmut K. C. Tessarek
    email = personal@email.com
    signingkey = xxxxxxx1

.gitconfig-work:

[user]
    name = K. C. Tessarek
    email = work@email.com
    signingkey = xxxxxxx2

Ok, now create a repo in ~/projects/personal/test/

then add a directory to that repo and commit

cd ~/projects/personal/test/
mkdir new-dir
git add .
git commit -m "new dir"

# committed with the correct user name and email, and signed with the correct key

cd new-dir
touch file
git add .
git commit -m "new file"

# error: name and email are empty, key is empty to

Run:

git config -l --show-origin

No entries for name, email, signingkey

Cheers,
  K. C.

-- 
regards Helmut K. C. Tessarek              KeyID 0x172380A011EF4944
Key fingerprint = 8A55 70C1 BD85 D34E ADBC 386C 1723 80A0 11EF 4944

/*
   Thou shalt not follow the NULL pointer for chaos and madness
   await thee at its end.
*/