I can't see the video. Not supported or something to that effect.
There is always the possibility, though extremely slim, that somehow the bolt has rusted to the inner sleeve. But it's a zinc plated bolt from the other pics, correct? And the sleeve is probably plated as well? Any grease or anti-seize in place? If it was stainless and stainless, I could see things jamming/galling up. But plated on both? The words "slim chance" don't even come close!
But either way, why are you messing about with any kind of alignment? You're not trying to center the axle at this state, are you? And neither toe-in, nor camber/caster are effected by the trackbar. Or are you messing about with aligning the trackbar and draglink? Now that would mean removing the bar most likely!
So unless you really have to remove it, just step back and curse at it from a distance. No more loss of hair of sanity for a few minutes/hours/days/weeks/months/years (oh no!!) if you don't have to.
But if you're messing with the bracket height, start whacking it again!
How long is the shank? How many threads inside? Did you fully torque it during the last installation? Just wondering if the shank had pulled through the bracket and the threads got distorted when torqued.
Looks like a high grade bolt, so a distortion is not likely unless you used an impact gun.
If the sleeve was long enough, and you torqued it hard enough, perhaps the inner sleeve is what's distorted and clamping on the bolt to the point that the threads are catching.
Did the bolt come out at all? Or is it stuck fully right up to the head?
And lastly, speaking of air guns... Do you have an air-chisel? Maybe a punch head on it and let it fly on the bolt.
Just be sure to wear ear protection!
Paul