According to Server Settings – Bandwidth and Transcoding Limits
Note : If the deep analysis for a file hasn’t yet been performed, your Plex Media Server will assume a
[2 x average bitrate]value if it’s needed for streaming limitation calculations.
At most of the time, I remotely played larger video always need to wait for loading. tbh, 2 times average bit rate bandwidth is really not enough for smooth experience. We need setting for how many times average bit rate for video.