Page Layout/CSS issues when enabling SSL (Nginx)

I just ran into this issue, but when setting up Caddy as a reverse proxy. I had to set APP_URL and ASSET_URL in /opt/librenms/.env to https://your.fqdn.com and reload services. This solved the CSS part, but AJAX queries were still over HTTP. To resolve that, I set the X-FORWARDED-PROTO header to https, and it began to work properly.