Well, there is an easy workaround for this.

On page load run this script:

$('.input-group').each(function() {
  $(this).find('label').css('margin-left', $(this).find('div.input-group-prepend').width()).css('margin-left', '+=0.25rem');
  if ($(this).find('.validate').length) {
    $(this).css('margin-bottom', '2.5rem');
  }
});

Put focused label above the bootstrap default z-index level for input-groups in your CSS file (3)

.input-group {
  > .form-control:focus +label,
  > .custom-select:focus +label {
    z-index: 4;
  }
}

Hi,

for now, we don't have outline styles for input group. We will implement them in the future.

Best, Marta