No, it is definitely NOT fixed in todays alpha release.
Can anyone confirm ?
it is for me
v1710.170828-1900
Strage.
I am definitely on the build that released today (version string you mentioned).
But both PLEX and the official Media player app still show grey bars.
Please => anybody else can comment on this?
EDIT: To be sure: You are playing a video with 2,35:1 aspect ratio and not a 16:9 video which has the black bars included in the video stream?
Its the same movie as in the OP bro. Almost the same frame 
perhaps you need to unplug the xbox for 30 seconds, push the power button for 10, plug it back in? That’s the only way to clear the cache as of right now. I’m grasping at straws why it’s fixed for me and not you.
Also confirmed via others on Reddit that it’s fixed for them.
But, to satisfy, here is a screenshot of the specs
@mrexcuse said:
Any changes to HEVC support and green screen issue with the latest xbox update?
10bit HEVC’s play just fine since the 08/07 Alpha. I haven’t seen a green screen issue.
OK I see that you are indeed watching a 2.35:1 video … I am still hoping some other user lets us know if I am the only one with grey bars or you are the only one with black bars 
What I also noticed in the official media player: When starting the video I had for maybe 1/4 second black bars, then they immediately switched to grey. Maybe it has to do with the TV connected and in my case xbox switches the RGB/HDR mode after starting the video and produces these grey bars.
Do you have a HDR enabled TV? - I do not.
Anyway: Have reported it via the insider app again.
FYI: Did a hard reboot (again) and played around with the color depth and YUV settings => no change.
@mike4001 said:
Do you have a HDR enabled TV? - I do not.
negative. It’s a 3yr old Sony Bravia. OG XB1, HDMI & Optical.
I’ll have my daughter check on her XB1S later tonight if you like. Also a non-HDR TV, but it’s 3 months old.
I was watching movies prior to the update with grey letterbox, took a break to update the XB, and went right back to watching and I noticed the black letterbox.
I checked several movies on the new update and they are all looking fine for me now.
No mention of this fix in the release notes, although they do mention that 4K movies will result in crashes at this time across all apps, FYI
@xetnez Yes would be nice to check your daughters xbox one S
Are you and @kingshillbilly maybe on a standard Xbox One? (EDIT: now I see you wrote OG XBox)
I am on an S. Maybe thats it.
Anyway: Thank for the info to both of you. I will just keep submitting feedback 
Also on an S, also still having this problem. Maybe it’s related to the HDR capabilities? I don’t have an HDR screen.
Fixed for me on latest Alpha update
Day One Xbox
I’m on a day one xbone, working correctly now. Make sure to submit feedback if you are still having issues.
OK my wild guess here:
OG Xbox One is fixed
Xbox One S is not fixed
Confirmed still an issue on my Daughters XB1S.
Original (black) XB1: Black letter-box bars as it should be.
XB1-S (white): Grey letter-box bars, this is bad.
To make matters worse, seems the grey is brighter now.
Freaky.
Thanks for confirming.
I just submit a bug report every new build.
Hope everyone who is having the problem does this.
I am having the same problem on my Xbox One S. I reported through the Xbox Insider App.
I do hope this gets fixed soon.
Same issue on Xbox One S. It’s definitely an Xbox issue and not a Plex one. Was having the same issue within the BluRay app a week ago.
