Power phase issues

Equipment :
Assioma duo shi
Garmin 530
Tcr sl2
Cleats are Shimano spd-sl

As the picture above, my concern is the point of power start and end, is that unusual or not ?
Plus, when I train for 1.5 hours zone 2, my quads usually get soreness first, but my heart rate is normal between 136 to 145, is this problem due to my weak body or the wrong setting of my bike ? Thanks for answering.

p.s I started cycling for 8 months.

Powerphase is really early compared to mine. Do you feel quad heavy? Do you lose control at the bottom of the pedal stroke?
My money is on seat heigth being too high.

I think the muscles engage the most are my quads, and there is a bit feeling of losing control at the bottom, so maybe my seat height is too low?or should I move saddle forward or backward?

Try lowering saddle first.

With respect to power and saddle height, each is important and should be reviewed together, not separately. Meaning, I’d hesitate to change the saddle height without seeing and evaluating your fit on the bike along with the power info.