Those errors should not have anything to do with PHP version. I am not sure what you are trying to say, as far as I am aware, there are no SSL related compatibility issues. You simply need a certificate on your server and your SSL/TLS mode in Cloudflare set to Full (strict).
As for 520 and 525 errors, they are generally caused by your host.
A 520 error occurs when the connection started on the origin web server, but that the request was not completed. The most common reason why this would occur is that either a program, cron job, or resource is taking up more resources than it should causing the server not to be able to respond to all requests properly. Review the Quick Fix Ideas in this Community Tip for troubleshooting suggestions.
A 525 error is typically caused by a configuration issue in the origin web server when its SSL certificate is not properly set up. Review the suggestions in this Community Tip for advice & insight.
If you have Cloudflare enabled through Bluehost’s partner integration, rather than a full setup through Cloudflare, there is not a lot we can do to help and they will need to help you resolve this.