From the video, it appears you don't have an issue with feeding.
Unfortunately earlier was a WHOLE different story. This same scenario happened yesterday, I think the first feeding they act very stubborn, then when they realize I walk away and dont feed them, that when i do come back hours later they realize they better eat whats given to them? Just a theory, dont know if fish can think like that, although something tells me they can. I mean, their instinct in the wild tells them to seize any opportunity to gorge themselves due to not knowing when their next meal is..?