Plex AP TV Blocked even when i have secure connection locally and with my domain

[Thorrrr]

Hi Guys

I need some help as an amateur to OPNsense I have done some extensive reading, but I am sure you appreciate it is a long road to fully understanding this software and subject matter.
I am trying to get the app.plex.tv to connect as a secure connection.
 
Weird thing is my local and domain connection shows fully secure.
But to app.plex.tv is shows as insecure, see https://i.imgur.com/4CcPbdp.png ?

From reading I looks like OPNsense is responsible for this. I saw this article which led me to this conclusion see https://support.plex.tv/articles/206225077-how-to-use-secure-server-connections/. 
 
The bottom of the page relates to PFSense and some kind of DNS Resolver, but not sure what to check or how to configure it correctly.

I did try last week adding this https://i.imgur.com/AE11VCt.png but made no difference

Update I have checked DNSMasq Log
https://i.imgur.com/Rv6FgU1.png

Please can somebody help me what to check and how to configure

PLEASE NOTE THIS IS RESOLVED

[TheRiceKing]

I hate to necro bump this but I'm having the exact same issue.

Update: NextDNS was blocking "plex.direct" so I white listed it then everything worked perfectly.

[spetrillo]

Its under Unbound...

You need to add the Mimugmail plugin called os-unboundcustom-maxit. Once you do this you will find a new section added in Unbound called Custom Options. You will add server:
private-domain: "plex.direct" and save the section. You will then have secure access.