Flexiforce sensor sinusoidal noise with no load

I have a Flexiforce 25lb sensor (0.375" dia. pad) connected to a SparkFun RedBoard. I’m trying to calibrate the sensor and I can see the voltage/resistance readings in my Serial Monitor but for some reason, with no load applied, the sensor drifts in a sinusoidal pattern, high and low alternating. I have left it on and reading for an hour or so to see if it would settle but it has not. The hookup guides and user manuals are lacking in any actual technical information on how to use these things. I searched the SparkFun, Adafruit, and stackexchange forums with no luck. Has anyone else had this issue? Is it a faulty FSR? I just bought it from SparkFun and this is the first time using it.

I have 3 10k Ohm resistors in parallel between my analog read in pin (A0) and the output from the FSR.

I’ve tested the solder joints and found continuity across all.

Can you supply a diagram and photos showing how you have things connected?

Is your power supply voltage nice and clean?