Test file to show Bootstrap 4.1.1 bug. Clicking on checkbox button's checkbox square is not toggling checkbox.

bs4_checkbox_does_not_toggle

<!-- Load in Chrome Version 67.0.3396.87 (Official Build) (64-bit) on Mac OS 10.13.5 -->

<!-- Click on the white square in the button that is the checkbox.  It will NOT toggle.  Click on button toggles. -->

<div class="btn-group" data-toggle="buttons">
  <label class="btn btn-primary active">
    <input type="checkbox" checked autocomplete="off"> Checkbox 1 (pre-checked)
  </label>
  <label class="btn btn-primary">
    <input type="checkbox" autocomplete="off"> Checkbox 2
  </label>
  <label class="btn btn-primary">
    <input type="checkbox" autocomplete="off"> Checkbox 3
  </label>
</div>