Having unique trouble with Synology Reverse Proxy and Home Assistant

I am running Home Assistant through Docker on by Synology NAS. Things have worked great for a long time… but I recently moved and now I am having issues. New house. New ISP. New Modem.

In Synology DSM, I am using a DDNS through Synology.me… lets call it jaxel.synology.me for example (not actual url). I am using the DDNS to access my NAS directly over the web. The certificate for this DDNS is a WILDCARD certificate from LetsEncrypt.

In addition to the DDNS, I am using Synology’s Reverse Proxy system to add subdomains for my various docker containers… for instance, I would go sonarr.jaxel.synology.me to access my Sonarr container. ALL of my subdomains are set up in the following format, and they ALL work properly, except Home Assistant:

Working great for Plex, Transmission, Sonarr, Jackett, etc… without issues.

In my Home Assistant configuration.yaml, I have the following lines:

# Required for DDNS
  use_x_forwarded_for: true

Now I have quirks with Home Assistant… SOMETIMES going to hass.jaxel.synology.me works, for about 10 minutes. Then it dumps me out and returns the Unable to connect to Home Assistant. Retrying in XX seconds... error. It will randomly start working again in a few hours, again for about 10 minutes. I can connect no problem using the direct IP of my NAS

The odd thing about this, is it only seems to happen when I am connecting via my LAN. If I disconnect from my local network and instead use my cell phone’s internet, I can connect using the hass.jaxel.synology.me URL without issues (but then of course, I can’t use since I am not on the LAN).

Does anyone have any ideas on what my issue could be?