I agree with what both Quantum and Ted wrote, and I had a version of what Ted described quite some years ago when I studied violin.
The teacher you consulted
.... she had me working on some pieces emphasizing the hands movement in order to have better control over the dynamics, but unfortunately this didn't have much effect on the issues I'm experiencing with my ring finger.
First I noticed
pieces emphasizing hand movements. Second, that the goal was the outcome (dynamics). We see this with some teachers, where pieces do the teaching - if you play these pieces, you'll get the desired skill by playing them. Often they seem to be traditional teachers, with a reputation (have good, advanced students, good interpretation of music). Pieces can have a particular thing: dynamics, or chords, or pedal, but you must also know
how to do these things (physically), and working on a piece won't necessarily cause physical playing changes to happen. Meanwhile, if you already play advanced music and sound good, a teacher without the eye for it, may not see things and be fooled. (My violin teacher said once, when I could do vibrato on one finger, only that finger, only briefly "When I close my eyes, I could be jealous." I'm a singer so I had the sound in my ear - but not the physical overall motion. "closed eyes" can be a metaphor).
You also used the word "finger(s)" a lot. The body works together, and in a sense it's not the fingers that play the piano.
The next thing, I don't want you to go to this detail, or try to "fix" it, or work with it in any way because what Ted said here:
and whatever you do refrain from trying to force control.
this is correct.
I found two of your videos here. He play well, fluidly, and in both, your knuckles are sort of flat - I can duplicate it because it's one of the things I used to do, and it makes my fingers tense and the wrists get tight too, but lotsa control in the fingers. DO NO try to "fix this" by trying to do things with your knuckles, because of what I just wrote. Do what Quantum and Ted say - experiment, explore, get to know how your body works together. A thing felt in one part of the body may be connected to another part of the body.
There may also be a teacher or two out there who specialize in this aspect of it. Piano is a "sport" as was said. There are also things like Alexander Technique and Feldenkrais, which work on body awareness, natural movement, and sometimes work directly with musicians. There can be an Alice in the Looking Glass, where you walk away from the house in order to get into the house.
For my own thing, I just spent over a month every day practising a Feldenkrais pattern of "stand up/sit down" from a chair with arms over my head, then folded, then dangling - chair in middle of room - then one foot in front as if with a pedal. It seems preposterous as "piano practice". But it got stuff to coordinate differently, and it did something for piano. The way I lean forward (first part of "stand up"), where I put my weight, the way I arched my back or created a dowager's hump (two 'failed strategies') affected what happened in my feet, hips, and back muscles.
Thing is, if you are musical, you will aim for the kind of sound you want to produce, and may do less effective things with the body to produce them. It takes a special kind of teacher to not be fooled by the sound. Or think that aiming for the sound will fix the body. (sometimes it might)
Another thing personally: I looked "classical" - like a picture book - for some of what I did for both instruments. I consulted a violin teacher who sighed, "I wish my students' left hand looked like yours." since I had the desired rotation, and
then some - but "looking good" isn't where it's at! (My piano hand also looked "classical" btw.)
It CAN be an interesting road of discovery, and it can be far reaching beyond piano. One weird thing about ease and comfort: whatever we do is our norm. When you first play with more ease, because you're doing something differently, you go "Oh. That's what ease felt like? I thought what I've been doing was natural - but in comparison to this new thing, man it was tense." (personal anecdote)
I'm still working my way out of my own doodoo, so I am no authority whatsoever on this.