I found this other forum post. Setting it to “Flexible” and changing NGINX to not enforce HTTPS for now works, and as I got busy with work, its my solution until I can look into it more on the weekend. Sadly, no response if they ever got it fixed.
From what I can tell, NGINX is “listening” on port 443 but not actually accepting any connections on the port anymore. I tried looking through all the config files and checking things that way, but no luck. Hopefully I can make more progress this weekend.
The fact that this isn’t solved already seems to indicate we’ve hit some sort of Edge case, and so there isn’t a lot to go on for it, sadly. A fresh install of NGINX on Truenas had the same issue, so… unless no one else is currently installing NGINX, seems like its something with our base setup. Maybe a bad image? No idea, but yeah. I’ll dig in more this weekend. Good luck.