Recent degradation in picture quality, when there were no changes to settings. Can anyone advise?

server-mac

#1

New PleX user here (one week in) and loving it. However, after an upgrade to the latest version (1.8.4.4249), and a reboot of my Mac, I noticed a degradation in picture quality. A 1080p, 8gb mkv file now looks like it's barely at 720p picture quality (watching this on an Xbox One connected by ethernet). I'm noticing this problem on both of the devices I'm streaming to (Xbox One and Amazon FireTV). None of my settings (default, including remote access) had been changed prior to me noticing the problem. I tried to adjust transcoder quality ("Make my CPU hurt") and transcoding x264 preset ("Very slow" as it states that slower values result in better video quality). I'm even running all of this on Ethernet, not WiFi. Now the video is freezing intermittently.Can anyone provide advisement?