Push to a remote repository : Host key verification failed


I am tying to sync my gitlab with another git repo but I get :

Fetching remote remote_mirror_08b3fe6fa472c152316d42ee8340196b failed: Host key verification failed.fatal: Could not read from remote repository.

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

I have tested with command line like : ssh git@server and I can connect to my remote with pubkey.

I use : gitlab-ce-11.2.1 and centos 7.5.1804.

Thanks for your help,

Got that one today. How did you solved it?