A 524 error indicates that Cloudflare made a successful TCP connection to the origin web server, but the origin did not reply with an HTTP response before the connection timed out. Review the suggestions in this Community Tip for troubleshooting ideas.
A workaround I recommend is using a Local Hosts file on the admin’s home computer so they go direct to server without the 100 second timeout limit.
https://www.howtogeek.com/howto/27350/beginner-geek-how-to-edit-your-hosts-file/