I have a critical error on my WordPress site. When I check the logs, I see that some files are missing (class-wp-html-doctype-info.php and class-wp-html-processor. in /www/html/wp-includes/html-api) Indeed, they are not in the expected location. So, I download these files from the official WordPress site and upload them to the server. After doing this, the site starts working again. However, after a few hours, the same problem occurs, and the files I added disappear again. What could be causing this issue? How can I fix it?