Where is the FTP server name in my inifinityfree?

[Admin]

Seeing how the ftp-deploy-sync-state.json file exists on your account and in the right directory, it means that the GitHub Action is able to upload the files to FTP.

So it seems that uploading files works, however this specific CSV file is causing problems.

Did you read this article already that @Frank419 shared?

Why are my files deleted after uploading them

Sometimes, when you upload a file, the upload is completed but the file is deleted immediately afterwards. This is usually caused by one of the following issues: The file is not in a htdocs folder All websites files must be uploaded to either the main htdocs folder, or to the domain specific htdocs folder (like example.com/htdocs). You cannot upload files to other directories on your account. If you try to create or upload files anywhere else, they will be deleted automatically. The file type…

Especially the file size limit is something to be aware of, which should be 10 MB for a CSV file. How big is the file you’re trying to upload?

And have you tried uploading this file with the file manager or a desktop FTP client also?