In the version I was using (4.5.3 Pro) it had some extra left spacing which I had to add -15px margin to fix. In 4.5.6 this seems to have been fixed but now there is no space to the right so .form-inline .form-check touch each other, as seen in the demo on this site. A checkbox on its own still has the left spacing which was present in 4.5.3. If you do something like: .form-inline .form-check .form-check /.form-inline .form-check the first .form-inline .form-check doesn't line up with the on by itself below. I could fix by putting it in a .form-inline but I have just overridden the bootstrap default padding-left I have fixed these 2 issues with the following:

.form-check {
  padding-left: 0;
}

@media (min-width: 576px) {
  .form-inline .form-check {
    margin-right: 1rem;
  }
}

---