Fix cPanel issue which affect WP Uploads

My domain cPanel’s File Manager refuses to accept any upload a file. from the attached screenshot, the upload reached 100% but didn’t finalize.

and I am unable to connect to my server via ftp. i will like to resolve this.

whenever I try to add a plugin or update an existing page, it does not allow and prevent page elementor editor to load. this might be as a result of the upload issue in the cpanel but need it checked and fixed.

On top of that the site goes down with a 503 Service Unavailable every day, but there’s no clear pattern to when it happens.

I need someone who can jump into WHM/cPanel, WordPress, and the underlying server configuration to trace the root cause, restore normal upload functionality, and eliminate the recurring 503s. Once you’re done I want to be able to:

• Upload files through cPanel File Manager without failures
• Install and update WordPress plugins and themes smoothly
• Edit any page without seeing a white screen or error
• Enjoy a stable site that no longer serves 503 responses

Please outline how you plan to diagnose the problem—whether it’s tied to PHP limits, mod_security rules, disk quotas, or something else—and the tools or logs you’ll rely on (error_log, access_log, WP-DEBUG, etc.). I’m ready to provide root or sudo access if needed and can schedule a maintenance window to avoid disrupting visitors while you work.