Unable to access Hass.io panel through proxy

Installation Home Assistant OS
1

I have been running Hass.io through my nginx reverse proxy for awhile, and until now, without issue.

I was unable to update from .60 to .66.3 through the built in updater due to errors, so I installed a fresh copy of .63.3. I am now unable to access the Hass.io panel through my proxy/domain. It works fine when accessed locally on my network, but when accessing through the proxy I get a blank screen and the following error in the logs:

data:text/javascript;charset=utf-8,class%20HaPanelHassio%20extends(window.hassMixins.NavigateMixin(window.hassMixins.EventsMixin(Polymer.Element)))%7Bstatic%20get%20is()%7Breturn%22ha-panel-hassio%22%7Dstatic%20get%20properties()%7Breturn%7Bhass%3AObject%2Cnarrow%3ABoolean%2CshowMenu%3ABoolean%2Croute%3AObject%2CiframeUrl%3A%7Btype%3AString%2Cvalue%3Awindow.HASS_DEV%3F%22%2Fhome-assistant-polymer%2Fhassio%2Findex.html%22%3A%22%2Fapi%2Fhassio%2Fapp-es5%2Findex.html%22%7D%7D%7Dstatic%20get%20observers()%7Breturn%5B%22_dataChanged(hass%2C%20narrow%2C%20showMenu%2C%20route)%22%5D%7Dready()%7Bsuper.ready()%2Cwindow.hassioPanel%3Dthis%7D_dataChanged(e%2Cs%2Ct%2Ca)%7Bthis._updateProperties(%7Bhass%3Ae%2Cnarrow%3As%2CshowMenu%3At%2Croute%3Aa%7D)%7D_updateProperties(e)%7Bconst%20s%3Dthis.%24.iframe.contentWindow.setProperties%3Bif(!s)%7Bconst%20s%3D!this._dataToSet%3Breturn%20this._dataToSet%3De%2Cvoid(s%26%26setTimeout(()%3D%3E%7Bconst%20e%3Dthis._dataToSet%3Bthis._dataToSet%3Dnull%2Cthis._updateProperties(e)%7D%2C100))%7Ds(e)%7D%7DcustomElements.define(HaPanelHassio.is%2CHaPanelHassio)%3B%0A%2F%2F%23%20sourceURL%3Dhttps%3A%2F%2Fhome.[redacted].net%2Ffrontend_latest%2Fpanels%2Fha-panel-hassio-ad7aa9a6055f74475fd3ba2c00bfe512.html.js%0A:0:0 Script error.

Normally, when clicking “Hass.io” the URL appends /hassio, then loads into /hassio/dashboard. Currently it just gets stuck on /hassio and doesn’t continue.

My nginx config has not changed since it worked last, and are as below:

server {
    server_name home.[redacted].net;
    listen 80;
    listen [::]:80 ipv6only=on;
    return 301 https://$host$request_uri;
}

server {
    server_name home.[redacted].net;
    listen 443 ssl;
    ssl on;

    #load ssl config
    include snippets/ssl-[redacted].net.conf;
    include snippets/ssl-params.conf;

    root /var/www/[redacted].net/html;

    location ~ /.well-known {
        allow all;
    }

    proxy_buffering off;

    location / {
        proxy_pass http://192.168.1.10:8123;
        proxy_set_header Host $host;
        proxy_redirect http:// https://;
        proxy_http_version 1.1;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection $connection_upgrade;
        proxy_set_header X-Real-IP $remote_addr;
    }
}

Any suggestions would be appreciated.