Deceptive site warning after setting up nginx for jellyfin server

[klunk]

Hi all.
After following the tutorial here https://forum.opnsense.org/index.php?topic=24778.0 I get a deceptive site warning from chrome / vivaldi when trying to connect to my jellyfin server. i have run the test that is mentioned at the end of the tutorial to check security and it passes with an A+ grade. Is there anyway to stop this warning appearing? I use a duckdns web address to access my jellyfin server away from home. Any help greatly appreciated.