First off, I like the way you are riding and I do like the horse.
Here's my take on the short clips.
First off, at the canter, you need to have her more forward, I would not be, at this stage, sitting in the saddle so deeply but have my weight more forward to allow her to use herself.
Secondly, I think the problem is arising from the fixation of your hands. This stems from you not allowing your elbows and wrists to be supple. I would bet that if I took hold of your wrist whilst riding alongside you, they would be as stiff as a board.
Carry your hands higher, so that your thumbs are on top and each thumb pointing to the diagonal ear. The only pressure on the rein should be from your thumb and forefinger the rest of your fingers are there to active movement when wanted.
It is a common misconception that people think they have good hands with a light contact when they are stiff in the wrist and elbow.
Think of being a piano player, arms supple!
When working youngsters I will usually carry my hands a lit higher than I would on a schooled horse..