It's easy to watch it happen. Just watch one youtube video that's outside your usual viewing subjects, and watch how your recommendations instantly change to try to suck you down a path on that new topic.
I have the opposite problem. Not sure which genius of youtube thought of it - but no matter how many times I reload it is always the same videos on the home page. Not taking any chances. yes there is a new for you, but if I haven't watched some videos for the last X hours, maybe the algorithm should take a chance with something random.
I agree, if it's shown you something a few times, and you haven't watched it, replace that suggestion with something else.
Every few weeks I end up with a new video card with button that takes the place of the video and it asks if i want to see something other than what it usually recommends. It's not quite as out there as I'd like, but it did shake things up a bit.
Just reloading won't help, you need to actively train the algorithm by telling it what videos you don't like and why. It also lets you stop showing recommendations from a given channel altogether.
On Facebook I've trained the algorithm to never show me any ads because I keep marking every ad that pops up as irrelevant and then 'hide all ads from this advertiser', and by also not following any celebrity, corporate or brand pages.