I use OBS Studio for all video encoding for both streaming and recording. When loading recordings to the timeline in Premiere Pro, the recordings playback in the preview window just fine. However, when loading a Twitch VOD into the timeline, playback would immediately drop frames and continue to lag. I found that the audio playback did not lag, unlike the video playback.
I used to not have this problem a few weeks ago. However, one time I launched Premiere Pro, and there was a pop-up window indicating that there was a graphics driver incompatibility issue. So I took action and downgraded the driver, but I still had the same problem.
At first, I thought maybe some sequence settings did not line up with the settings of the Twitch VODs, but I am no expert when it comes to this.