All my measurements fluctuate.

The ESC and the PWM signal may not be perfect, please understand that there is a limit on how accurate the signal can be and how precisely the ESC can react to the input signal. There are also other limitations such as the self compensation and PID control of the ESC given the change of voltage and to maintain a certain RPM.

When you observe all the measurements fluctuate higher than 15%: thrust, torque, current, RPM and/or voltage, please follow this guideline:

• Check the voltage if it is consistent. LiPo batteries may lose voltage gradually, power supply shall maintain a voltage when the throttle remains the same.
• Please make sure that the RPM is under fluctuation, this can be physically heard in the lab as the motor is making significant noise.
• If you observe the RPM remains stable in the GUI, check if the current is stable. Generally speaking, the RPM and the current shall follow the same path of regulation. When you observe a stable RPM but a fluctuating current, this can be a sign of a damaged current sensor. 
• If you find the RPM and the current are stable, check the thrust and torque value. Generally speaking, the higher the RPM shall come with a higher thrust; a higher current shall also come with a higher torque. If you find the result not matching this phenomenon, you may refer to the load sensor troubleshooting guideline.
• It is very unlikely that all the measurements (current, RPM, thrust, torque) fluctuate. The most likely reason that leads to this failure is the input PWM signal. Keep in mind that the PWM can sometimes be tricky and may differ with the ESC that you use. If you are using the Series 1585, you may try the RC Control Board that enables more control protocol:

https://www.tytorobotics.com/products/series-1580-1585-rc-control-board