Does Direct Stream/Play not work over WAN?



I'm having a problem trying to get direct stream or play to work over my WAN connection. I have enough bandwidth to make it happen but I just cannot get it work. These are all devices that are plenty powerful and have the typical HW decoders build into them. I just cannot get it work for some reason. Plays fine when I'm at home.

The reason is that I'm going to convert all my media a high profile VP9/MKV library. Why? Saves precious bandwidth and keeps the quality high. I was able to convert a 4.3GB episode to 1.5GB. That's a pretty substantial savings.

Why VP9? Because it is the same codec YouTube uses (until they convert to AV1) and damn near EVERYTHING on the planet has a HW Decoder for it. Also, I've noticed that starting a direct play a VP9 file is instantaneous. Like YouTube level click and it plays immediately. I cannot get the same to happen for my H264 encodes. This has a helluva perceived effect of quality of service.

One thing that baffles the hell out of me though. The Plex Web Browser Client does not support any of the next Codecs. Just H264. ¯_(ツ)_/¯


Would love to see support for VP9 in Chrome as well.
Also has anyone tested VP9 streaming on Android?