The categories widget block will collapse the number of subcategories if there are more than 5 subcategories. This can be fixed by changing the code quite easily.

This is the code for the category widget block:

{{$catClass = '\IPS\cms\Categories' . \IPS\cms\Databases\Dispatcher::i()->databaseId;}}
{{$categories = $catClass::roots();}}
{{if !empty( $categories )}}
	<h3 class='ipsWidget_title ipsType_reset'>{lang="categories"}</h3>
	<div class='ipsSideMenu ipsAreaBackground_reset ipsPad_half'>
		<ul class='ipsSideMenu_list'>
			{{foreach $categories as $category}}
				<li>
					<a href="{$category->url()}" class='ipsSideMenu_item ipsTruncate ipsTruncate_line'><span class='ipsBadge ipsBadge_style1 ipsPos_right'>{expression="\IPS\cms\Records::contentCount( $category )"}</span><strong class='ipsType_normal'>{$category->_title}</strong></a>
					{{if $category->hasChildren()}}
						<ul class="ipsSideMenu_list">
							{{foreach $category->children() as $idx => $subcategory}}
								<li>
									{{if $idx >= 5}}
										<a href='{$category->url()}' class='ipsSideMenu_item'><span class='ipsType_light ipsType_small'>{lang="and_x_more" sprintf="count( $category->children() ) - 5"}</span></a>
										{{break;}}
									{{else}}
										<a href="{$subcategory->url()}" class='ipsSideMenu_item ipsTruncate ipsTruncate_line'><strong class='ipsPos_right ipsType_small'>{expression="\IPS\cms\Records::contentCount( $subcategory )"}</strong>{$subcategory->_title}</a>
									{{endif}}
								</li>
							{{endforeach}}
						</ul>
					{{endif}}
				</li>
			{{endforeach}}
		</ul>
		<p class='ipsType_center'>
			<a href='{$url->setQueryString('show','categories')}' class=''>{lang="cms_show_categories"} &nbsp;<i class='fa fa-caret-right'></i></a>
		</p>
	</div>
{{endif}}

In this code you will see this snippet:

{if $idx >= 5}}
<a href='{$category->url()}' class='ipsSideMenu_item'><span class='ipsType_light ipsType_small'>{lang="and_x_more" sprintf="count( $category->children() ) - 5"}</span></a>
{{break;}}
{{else}}
<a href="{$subcategory->url()}" class='ipsSideMenu_item ipsTruncate ipsTruncate_line'><strong class='ipsPos_right ipsType_small'>{expression="\IPS\cms\Records::contentCount( $subcategory )"}</strong>{$subcategory->_title}</a>
{{endif}}

This is what control the behavior so all we need to do is to remove the top part of this and the ending endif. This will look like this:

{{$catClass = '\IPS\cms\Categories' . \IPS\cms\Databases\Dispatcher::i()->databaseId;}}
{{$categories = $catClass::roots();}}
{{if !empty( $categories )}}
	<h3 class='ipsWidget_title ipsType_reset'>{lang="categories"}</h3>
	<div class='ipsSideMenu ipsAreaBackground_reset ipsPad_half'>
		<ul class='ipsSideMenu_list'>
			{{foreach $categories as $category}}
				<li>
					<a href="{$category->url()}" class='ipsSideMenu_item ipsTruncate ipsTruncate_line'><span class='ipsBadge ipsBadge_style1 ipsPos_right'>{expression="\IPS\cms\Records::contentCount( $category )"}</span><strong class='ipsType_normal'>{$category->_title}</strong></a>
					{{if $category->hasChildren()}}
						<ul class="ipsSideMenu_list">
							{{foreach $category->children() as $idx => $subcategory}}
								<li>
									
										<a href="{$subcategory->url()}" class='ipsSideMenu_item ipsTruncate ipsTruncate_line'><strong class='ipsPos_right ipsType_small'>{expression="\IPS\cms\Records::contentCount( $subcategory )"}</strong>{$subcategory->_title}</a>
									
								</li>
							{{endforeach}}
						</ul>
					{{endif}}
				</li>
			{{endforeach}}
		</ul>
		<p class='ipsType_center'>
			<a href='{$url->setQueryString('show','categories')}' class=''>{lang="cms_show_categories"} &nbsp;<i class='fa fa-caret-right'></i></a>
		</p>
	</div>
{{endif}}