post-receive /var/www/html denied - wordpress

Question

My username (let’s call it my_name) belongs to the Apache group which is owner of var/www/html directory, sub-directories and files contained within.
In that directory I installed Wordpress. Directories and files permissions are set to 0775 (yeah, I know the files should have 644, but it is not a factor for now).
Well, my username has writing permissions indeed, because I am able to create new files or directories, as well as delete them, by using SSH terminal or WinSCP.
The problem comes up when I run a post-receive hook of a bare git repository, no matter if by running the script or by pushing changes from the local working repository.
In any scenario, the post-receive hook does not work because of permission denied. Really strange and I cannot understand why.
Could you help me please?
Edit:
This is the output of ls -alrth ~/git/devsite.git/hooks directory:
-rwxrwxr-x 1 name apache 896 Apr 2 22:41 commit-msg.sample
-rwxrwxr-x 1 name apache 727 Apr 7 09:09 post-receive
-rwxrwxr-x 1 name apache 189 Apr 2 22:41 post-update.sample
-rwxrwxr-x 1 name apache 398 Apr 2 22:41 pre-applypatch.sample
-rwxrwxr-x 1 name apache 1704 Apr 2 22:41 pre-commit.sample
-rwxrwxr-x 1 name apache 1239 Apr 2 22:41 prepare-commit-msg.sample
-rw-rw-r-- 1 name apache 1348 Apr 2 22:41 pre-push.sample
-rwxrwxr-x 1 name apache 4951 Apr 2 22:41 pre-rebase.sample
-rwxrwxr-x 1 name apache 3611 Apr 2 22:41 update.sample
This is the post-receive script:
#!/bin/sh
TARGET=/var/www/html/wp-content
GIT_DIR=/home/name/git/devsite.git
#run 'post-receive' hook
git --work-tree=$TARGET --git-dir=$GIT_DIR checkout -f

Answer 1

Try again after a
cd /path/tp/bare/repo
git config core.sharedRepository true
I mentioned it before in "Permissions with Git Post-Receive".
In the OP's instance, the post-receive script is not placed properly: it should be in ~/git/devsite.git/hooks, not ~/git/devsite.git.