Apparently the default keymaps for `contra` and `fractal` were derived
from some `planck` keymap which contained code to control the status LED
in the implementation of the `BACKLIT` custom keycode. Unfortunately,
the code to control the LED manipulated the `E6` pin directly, and it
was copied without changes, but the `contra` and `fractal` boards use
the `E6` pin in the matrix, therefore pressing the key mapped to
`BACKLIT` resulted in phantom keypresses for all keys in the
corresponding column.
Sergey Vlasov
Ryan
Merlin04