Ah, noted. Thank you!

Here is the oscilloscope result for Channel 1 (GPIO2):

I have some ESP-WROOM-32 modules and I noticed that the PWM voltage on GPIO0 does not actually go to 0V. PWM on other pins behaves as expected. Here is a pinout of the ESP modules:
WROOM Mini D1 Pinout.png


I attached the negative oscilloscope probe to the ground pin on the outside row of the ...

If you are using the Arduino IDE, then this forum post in the Arduino Forums claims you can use the following command:
pinMode(4, INPUT_PULLDOWN);


Forum URL for reference:
https://forum.arduino.cc/t/pullup-and-pulldown/657225

FYI, according to the following image, D2 is GPIO4, which should be ...