I've had this happen on certain times and like a sibling comment I also wonder whether it's YouTube trying to shed some load in busy times. Maybe even A/B testi

I've had this happen on certain times and like a sibling comment I also wonder whether it's YouTube trying to shed some load in busy times. Maybe even A/B testing what user profiles would notice and switch back manually and who wouldn't care enough. I've also seen it happen when a browser can't keep up, eg. freezes for quarter of a second due to excessive swapping or some OS thing fighting for resources.