FSR project (Arduino Nano)

We are experiencing problems with the generation of values in the serial monitor.

We have connected an Arduino Nano and a FSR to a breadboard. We referred to this tutorial and followed their setup and code. https://www.instructables.com/id/Interfacing-Force-Sensitive-Resistor-to-Arduino/.

With no pressure exerted, the values generated are more than 0, and fluctuate at around 200-400. Sometimes, the values drop to 0, but immediately go up.

We already confirmed that our Arduino Nano is working fine with the Blink test, and used different computers to run the code, and used different FSR sensors, and tried different circuit designs, but we keep facing the same issue and we do not know why.

Does anyone have a solution to this issue? Thank you!

but we keep facing the same issue and we do not know why

Your main problem is that like so many projects on that site it is crap.
There is no current limiting resistor on the LED which will damage your Arduino pin.
The 10K resistor needs to be connected to 5V not ground.

NEVER USE INSTRUCTABLES TO LEARN ANYTHING THEY ARE CRAP

A FSR must be part of a voltage divider circuit. Because of that the output will never be exactly 0V nor will the output ever be exactly Vcc since the resistance of the FSR is never infinity nor 0 Ohms.