From "Sound with ESP32 – I2S Protocol" - left vs right mixup?

I am enjoying the article "Sound with ESP32 – I2S Protocol" and got it working on my ESP32 with a INMP441 mic. The first listing, in line 32, says 

 .channel_format = I2S_CHANNEL_FMT_ONLY_LEFT,

and my mic was wired with L/R pin going to GND, as in your picture. But I see only "noise" in the Serial plotter. I saw some comments on the article that mentioned they had to switch from Right to Left, to get it to  work, likewise for me (either leaving the L/R connected to GND and editing line 32 to say

.channel_format = I2S_CHANNEL_FMT_ONLY_RIGHT,

OR leaving the code unchanged and wiring L/R to VDD.

Any clues as to what can be causing this?  Are some INMP441 made differently (mine looks exactly like the one in the photo)

Thanks,

Paul M