I've got this menu working when I release the mouse button over the "Menu Name" bit:
<button type="button btn btn-secondary" class="btn btn-default dropdown-toggle" data-toggle="dropdown"
aria-haspopup="true" aria-expanded="false">*Menu Name*<span class="caret"></span>
</button>
<ul class="dropdown-menu">
<li><a href="#">Do Something</a></li>
<li><a href="#">Do The Other Thing</a></li>
</ul>
This is a rails 6 app with lots of JS, using bootstrap 3 because that's what I learned from, and if I move to bootstrap 5 I get errors complaining about something called popper (sounds like the dropdown relies on it), and who knows what else will break if I continue -- looks like lots of things changed going from bootstrap 3 to 4, and then to 5.
So is there a straightforward way to do this?