Originally Posted by Falcenduro

After having the same issue today, it's led me here and I have figured it out. Hopefully can help others.
The problem is your sensor lead. It's either:-

A. Not plugged in the right way.
B. Not plugged in all the way.
C. Damaged (not likely).

Solution:-
A. (Make sure it's plugged in the right way).
There is a small locating tab on each side of both plugs. They slot into the motor and esc. It's possible to push the plug in the wrong way. Look closely.
B. (Make sure the plug is pushed in all the way). You can use a small flat blade screw driver to carefully push it in all the way, pushing on either side of the plug.
C. Try another sensor lead.

When I unplugged the the lead, the esc characteristics did not change. That's when I thought it may be the problem. Trying another lead, making sure it was in the right way and fully in, it worked. So I plugged in the original lead, making sure, right way and pushed in fully and presto, all good. 👍