Video playback in the native browser is mostly broken on my single sim XA2. More info at SFOS 4.5 feedback thread - #45 by dumol
Later Edit: Have flashed latest 4.4 and retried the EA update with no luck. Codecs are borked on my device with this first 4.5 version. It’s not only video, I’ve noticed Reddit videos have no audio at all in the native browser after updating.