your stroke looks as if you're used and confident with, and so relaxed to show some room for further improvement.
...I had actually tried keeping a pull buoy between my thighs but my right leg still went down a lot. I think I got used to this bad kick where I kick down a lot.
Yesterday, I tried to kick down only a little. But I won't know if I'm doing any better till I take another video.
From TI's point of view, you should forget using a pull buoy. It's much more useful to find the right balance with streamlined legs without such Tools, which are just masking the problems. Spearing somewhat deeper, TI says fingertips just below belly-depth, wrist a little higher, elbow above wrist and shoulder above elbow will be of great help. (Just now you're spearing upward, so your legs and Body don't have a chance to drift horizontal...)
Don't miss the fundamentals: Relaxed neck with weightless-felt head and 90° looking down, head-spine aligned (work on both SG- and Torpedo-drills in all variations are helpful...) Your spear from underwater looks as if your recovery is too tensed. Remember the elbow should lead the recovery in a half circled movement as far sideways as possible, lower arm and hand should just hang like shown by ragdolls.
Don't focus on your kick for now (in TI a well tuned 2BK comes even after breathing...). However if really necessary, focus in aligned and streamlined-straight-relaxed legs. Feet should not move more apart than the toes will have contact with the heel of the other feet.
Enjoy your way with best regards,