Sorry for the delay here! Somehow we missed this when you orginally posted it.
You’re right! The motion is not correct — it’s stringhopping. This is the problem with the “start slow, get faster” method. When you play slowly, it’s much harder to know if your motion is actually correct, because slow motions all feel kind of the same. Even if you are doing something correctly, the only way to test for that is to see if you can go fast, because only the correct one will speed up. So you’re back to square one of basically starting out with something that’s fast.
Believe it or not, the best part of this video is the bit at the end where you start going fast and everything gets random. Because that randomness is your body trying to find a way that is smooth and consistent. You’re basically demoing all these different motions when you do that — different wrist motion, bits of forearm, bits of elbow, all start creeping in. That’s your body trying to learn. And in there, around 1:01, is a nice looking DSX motion that is trying to emerge. It’s only just poking its head out, but it’s trying break free. If you can learn to recognize and encourage just that motion, it’ll start clicking at this speed and most likely faster.
This is what it’s like when you’re still in the initial stages of learning a new physical activity. It’s random and awkward and it’s hard to differentiate between all the motions that are happening. But now you know what you’re looking for - which is any motion that’s fast and consistent, doesn’t matter if it’s USX or DSX. Take whichever one is working and go with that.
Also, take a look at your form, specifically the range of motion. You’re moving on the radial side of the joint here. You want to be on the ulnar side. Here’s the overview:
If you don’t know what ulnar feels like, try this. Sit down in front of a mirror. Using your current form, play a downstroke on the G string and freeze with the pick at the lowest portion of the downstroke, resting on the B string. Do your arm and wrist appear straight in the mirror? If so, this orientation should actually be the start of your downstroke. Without changing anything, now play a downstroke on the B string and look in a mirror while you do it. Do you see an ulnar bend in the wrist? If so, that’s the correct range of motion — straight to ulnar and back again.