HTTPS breaks Phabricator style

When I attempt to access my website via HTTPS, I get a version of the website that’s stripped out of all styles. It is also flagged on Chrome as insecure. On inspecting the source, I noticed a bunch of “http” references to some resources like “favicon”.

Is that a known bug? And if so, are there known workarounds?

Reproduction Instructions
Complete steps which allow someone else who does not have access to your environment to reproduce the bug.
Install Phabricator on Ubuntu 18.04.3 LTS and Apache following official setup instructions.
Install SSL certificate from Let’s Encrypt using certbot.
Access the website via HTTPS. Actual live site (with issue) is accessible at https://ops.forgottenmines.com/

Phabricator/Arcanist Version
Output from Config > Version Information or arc version.
Phabricator Version: ccf28a81121ea21d72b342cfb8ab2eee4e56bf86 (Jan 30 2020)

Your phabricator.base-uri is probably set to the non-https version, so all the resource (like favicon and css) URLs are http. Fix it to be https, and maybe restart the server, it should fix the URLs to use https and work correctly (the browser would not load http resources initiated by an https page).

Thanks @avivey. That was exactly it, I totally forgot there was such a property and only focused on Apache.