Plex transcoding h264 files that previously never needed transcoding.

Sometime within the past few weeks or months, Plex has start transcoding videos while web streaming, when in the past it would never transcode and let me direct stream them in their original quality. The only plex clients that I use are the web app, android/ios apps, and chromecast. For all of those clients I have, for many years, been able to stream h264 1080p with no transcoding. Now Plex has started transcoding these files and it makes the videos look awful compared to before.
How can I force this to stop transcoding? If this is not possible or not fixed soon, I will definitely be canceling my plex pass (which I have had for at least 3 years now) and finding a new solution.