SSL Certificate Errors

Regarding the TV, this is what we know.

If your TV is one which is NO LONGER GETTING UPDATES then there’s nothing we can do except recommend you get a set top box for it. Nvidia Shield Pro, Roku Ultra, – something of that nature.

( My nephew has a 2.5 year old 4K Samsung with this problem. He grabbed the new Roku Ultra)

Regarding the certificate being UNKNOWN, Do you have your own certificate involved here somewhere? Perhaps attached / installed in the NAS itself?

If true, did you inform Plex of the certificate?