Is a bug of the plugin.
wordpress transforms the “heightPlaceholder” string to “heightplaceholder” (lower case)
Workaround:
Open bmi-calculator-shortcode.php
locate these two rows (lines 47 and 48):
$heightPlaceholder = $attrs[‘heightPlaceholder’] ?: ‘Height’;
$weightPlaceholder = $attrs[‘weightPlaceholder’] ?: ‘Weight’;
change with these:
$heightPlaceholder = $attrs[‘heightplaceholder’] ?: ‘Height’;
$weightPlaceholder = $attrs[‘weightplaceholder’] ?: ‘Weight’;
Enjoy