Hello, I designed a buffer circuit using two LM358, please refer to the attached picture. A 1KHz, 2.19Vpp sine wave was applied to pin 3 of U1. However, as a result of measuring the waveform at output pin 1 of U1, the output is similar to the half-wave rectified waveform. The output voltage goes to zero. I designed a simple buffer circuit, but I would like a solution for this.