I am designing a passive high pass filter, here are the values: 2 MΩ and 1 uF cut-off frequency is 0.07 Hz +-20 V and when I apply a 1 kHz sine signal, I get such a result. What is the reason for this? The voltage level looks like this. I'm using Pspice. When I keep the cutoff frequency constant and normalize the resistance value to smaller values, the filter response seems to return to normal.
Somehow your sinewave frequency was set to 1Hz. The Probe plot indicates that and is a correct waveform for R3 set to 2 milliohms. Change R3 to 2MEG, the value that you want. You can look at the output file to see what the sine frequency is set to.