Ffmpeg: tls: error:0A000086:SSL routines::certificate verify failed (Plex player for Windows)

Issue is resolved.
I re-exported the pkcs12 certificate using the method: Plex Media Server 1.32.0.6918 custom certificate must be regenerated with new OpenSSL arguments - #9 by ChuckPa

So if anyone has this issue, check your own custom pkcs12 certificate.