The site looked like a standard new WP installation until I issued the certbot command and selecting the option to redirect all traffic to the https version. Then it turned into what you see now (see below for details).
Please fill out the fields below so we can help you better. Note: you must provide your domain name to get help. Domain names for issued certificates are all made public in Certificate Transparency logs (e.g. https://crt.sh/?q=example.com), so withholding your domain name here does not increase secrecy, but only makes it harder for us to provide help.
My domain is: osspix.co.uk
I ran this command: certbot --apache
It produced this output: certificate authorised and configured, along with apache virtual secure domain
My web server is (include version): Not sure I understand this question. It’s a racked server which I rent. Is that what is meant?
The operating system my web server runs on is (include version): Debian 9 (Stretch)
My hosting provider, if applicable, is: self-managed by shell access
I can login to a root shell on my machine (yes or no, or I don’t know): Yes
I’m using a control panel to manage my site (no, or provide the name and version of the control panel): No
The version of my client is (e.g. output of certbot --version or certbot-auto --version if you’re using Certbot): certbot 0.28.0