The fix for this Plex Media Player issue was actually released in version 2.18.0
The Release Notice text was missed and it has now been added See Plex Media Player
Could you confirm that the issue is now fixed.
I can confirm it’s fixed for the web player Version 3.57.1 and the latest XBox One client. I reproduced the issue on the Mac PMP 2.10.0 as a baseline to make sure I still had the right media. After upgrading to Mac PMP 2.19.1 the issue is fixed.
Thanks again for the support.