Well, you seem to have gotten rid of the straight upright body position during the ball strike, so it's progress.
Now, you need to learn to hit only flat serves when messing with your motion. You hitting spin serves, there's no way to know if you have any real improvement in HITTING the ball, which is the whole key to serving.
The motion is secondary. The actual RESULT of the ball is the whole point of working on your motion.
Your one serve, back few, shows a pathetic 3.5 looking top/slice that bounces about 4' before the backwall......on an INDOOR court. Most indoor courts have abrasive surfaces, the ball bounces HIGHER indoors than outdoors.
And, no need for any technique change if you swing slow.
Swing fast, hit FLAT, and see what the ball does.