Mine is a CakePHP project. For some reason, only 3 files in the root folder is getting uploaded to staging. It upload only .gitlab-ci.yml, README.md and .htaccess files. It skipped index.php file and all sub folders. Is there any problem with the .gitlab-ci.yml file
If I read the lftp manual correctly, your mirror -R ./public_html expects both a local and remote public_html directory right?
What kind of runner are you using? shell? You could try to reproduce your script commands in the build directory on your runner to see what happens when manually executing the commands?