[BUG] 4 level multilevel sidebar vertical menu only shows 3 levels

[Capt-Zeanie]

Unable to produce more than 3 levels in sidebar vertical menu. I can do 3 levels but not 4, is this by design or a problem? Here is some code for a 4 level menu (3 categories and the 4th level is for articles)

<li class="nav-item"><a href="#" class="nav-link"><i class="nav-icon fas fa-circle"></i><p>Lampposts<i class="right fas fa-angle-left"></i></p></a>
	<ul class="nav nav-treeview">
		<li class="nav-item"><a href="#" class="nav-link"><i class="far fa-circle nav-icon"></i><p>Small<i class="right fas fa-angle-left"></i></p></a>
			<ul class="nav nav-treeview">
				<li class="nav-item"><a href="#" class="nav-link"><i class="far fa-dot-circle nav-icon"></i><p>Bulbs</p></a>
					<ul class="nav nav-treeview">
						<li class="nav-item"><a href="#" class="nav-link"><i class="far fa-dot-circle nav-icon"></i><p>Article 1</p></a></li>
						<li class="nav-item"><a href="#" class="nav-link"><i class="far fa-dot-circle nav-icon"></i><p>Article 2</p></a></li>
					</ul>
				</li>
			</ul>
		</li>
	</ul>
</li>  

Environment:

• AdminLTE Version: 3.2.0
• Operating System: Linux Raspberry Pi OS
• Browser (Version): Firefox Latest

Thank you for reading