GitHub organization project SSH URL can't push

ssh
github

#1

I found out that when I create a project using a GitHub organization repo SSH URL, I could not git push it.
For example, a project of git@github.com:TCLResearchHK/VRWorkshopHKOSCon2017.git

andyli:~/workspace (master) $ git push
Warning: Permanently added 'github.com,192.30.253.113' (RSA) to the list of known hosts.
ERROR: Permission to TCLResearchHK/VRWorkshopHKOSCon2017.git denied to andyli.
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

But I clearly has push access, and the git push succeed if I use the HTTPS URL instead.

Interestingly, the issue only happens if I use a GitHub organization repo, but not a personal GitHub repo. i.e. When I created a project with the SSH URL of a fork repo of the same project, git@github.com:andyli/VRWorkshopHKOSCon2017.git, the push succeed.