Colour darkest grey-shade returns an empty cell

[mtsweir]

I entered the darkest shade from a grey scale system: #101114, Grey 900.

And the white-on-black cell is empty, here are the values that were entered:

Rows

#f7f7f8, Grey 100
#eeeff1, Grey 200
#e6e7ea, Grey 300
#d2d4da, Grey 400
#abb0ba, Grey 500
#676e7e, Grey 600
#40454f, Grey 700
#202227, Grey 800
#101114, Grey 900

Columns

#FFFFFF, White
#101114, Black

See demo: Contrast Grid URL