I don’t know if this behaviour is actually specific to the Bullseye test build or not, but if it turns out not to be, then feel free to split this into a different thread.
Anyway: there’s an issue here with the logic of choosing a default playback resolution with whitelisting active. I’ve been watching some standard definition stuff on iPlayer lately, and the video typically has dimensions of 960x540 (frame rate 50Hz). The standard resolution it plays this at is 576p/50 - meaning it is being downscaled horizontally from 960 pixels to 720, with some consequent loss of detail. Whitelisting resolutions should never cause the video to be downscaled - that’s part of the reason for using a whitelist. It should be upscaling to 720p/50 or 1080p/50 instead.