Doesn’t your mobile menu (aka hamburger menu) go away when implementing the recommended solution? I can’t seem to have my cake and eat it to on this bug…
I think a good solution to this issue, is to use Hamburgers.
Here is the button toggle markup with Bootstraps default class and data-toggle & data-target attributes added.
<button class="hamburger hamburger--vortex navbar-toggler" data-toggle="collapse" data-target="#navbarSupportedContent" type="button"> <span class="hamburger-box"> <span class="hamburger-inner"></span> </span> </button>
It may not be the best solution for everyone but it is very easy to use, light-weight and provides nice functionality.