The Alexa/Plex problem IS FIXED!  In some ways, better than ever.

I was notified by the Echo support supervisor by phone message this morning.  There was still some issues I had to fix myself, e.g., some of my previous settings were deleted like the default server (my My Cloud NAS) so I had to reset it for every Alexa device.  I even got it to work via the Alexa app voice button on the iPhone app. Right now, I am listening to Plex play music on iPhone via the Alexa button and listening to phone through Bluetooth headphones.

This is a very cool way to enjoy using Alexa to control Plex functions. 
If you want to do same, see this Plex weblink:
https://support.plex.tv/articles/115000320808-getting-started-with-alexa-voice-control/
 

I use the anypod skill to play podcasts on my echos. Once it’s enabled you can just say Alexa ask anypod to play X podcast and it will play.

RECENTLY I HAD A VALVE REPLACEMENT OPERATION IN MY HEART, AND THE HOSPITAL INSERTED ME A PERMANENT PACEMAKER. SINCE THEN I NOTICED MANY OCCURENCES OF AN INTERRACTION BETWEEN THE PACEMAKER AND ECHO SPOT ALEXA. WHEN I WALK SOMEWHERE IN ITS PATH, ( BETWEEN WIFI AND ALEXA) IT SAYS THE HOUR AND SOMETIMES IT ADD A PHRASE THAT SOUNDS LIKE ( IMMEDIATE ACTION ....SOMETHING.... DISCONNECTED)

Up until recently I had just an Echo Dot in my Living Room.  I just bought a Vizio PQ-65F1 TV which is SmartCast enabled and can be controlled via Alexa.  I also just added an Echo Plus to the mix.  I moved my Echo Dot to my bedroom and have the Echo Plus in my Living Room next to the TV.  Both are enabled and the SmartCast Alexa skill is enabled.  For some reason the Echo Plus will do all commands like turn on/off tv, change channels, change inputs, but it won't turn up/down or mute the volume.  If I give these commands to my Echo Dot, it performs them flawlessly, including to increase and decrease the volume.  I'm wondering why the Echo Plus will only do some of the SmartCast Alexa skill commands? 

I've reached out to Amazon Alexa's customer service and they've created a ticket.  I also reached out to Vizio Support via reddit and they're looking into it. 

I'm just wondering why my SmartCast enabled TV is capable of all commands working with my Echo Dot, but the Echo Plus won't do the volume controls?  They're all connected to the same network.  I've tried enabling each Echo separately.  I've reset the TV.  I've disabled and reenabled the SmartCast skill.  Nothing seems to work.

Apparently I am not alone.  I can play from Plex in all the ways I can except via the Alexa skill; it seems to be hosed.  The ways I can play is via my Plex home page through browser on Win  laptop, via Roku to TV, and to iOS phone and iPad.

I even checked out the latest Plex app installed in my WD NAS and reverted back to the previous version.  No luck. 

BTW, the mymedia app has some drawbacks -- it requires a PC running the app to be on, whereas Plex is running on a network connected WD My Cloud NAS which is always running and accessible to ALL devices on the network.  Plus, Plex has many handy features.

I just need to get Amazon to fix the darn Plex skill at this point!

skills are the responsibility of the developer, not amazon.  most likely at the bottom of the skill there is a link where you can get help. 

yea, there are some difference between my media and plexi,  but you can install mymedia on nas.