Serial Plotter Understanding

I used two POT in arduino and i'm transmitting these two POTs' value using nrf24l01... when i opened serial plotter from the transmitter arduino, i saw one POT's value is going ahead of 2nd POT's value and 1st POT's value is going at a faster rate than the 2nd POT's value. why it's like that??? please help me understanding this. I'm a beginner.

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