Custom point icons / sorting problem

Based on the doc, I created my own zip file with icons. The groups are created, but I have a problem sorting the icons by name. As you can see in the screenshot below, the icons are not sorted.

I added an entry <sort>name</sort> to the xml file

<?xml version="1.0" encoding="utf-8"?>
<items version="1">
 
	<!-- container with item meta information -->
	<item>
		<version>1</version>
		<name>
			<def>Flags / test</def>
			<pl>Flagi / test</pl>
		</name>
		<creator>Endrju</creator>
		<publisher>Endrju</publisher>
		<description>
			<def>Custom icons for Locus Map app</def>
			<pl>Spersonalizowane ikony dla aplikacji Locus Map</pl>
		</description>
		<date>2025-09-27</date>
	</item>
 
	<!-- container with meta information about item content -->
	<content>
		<!-- sort options, 'content' for original sort as packed in zip, otherwise sorted by name -->
		<sort>name</sort>
 
		<!-- category 1 -->
		<category id="Several European flags">
			<item file="Polska.png" />
			<item file="Chorwacja.png" />	
			<item file="Włochy.png" />
			<item file="Ukraina.png" />
			<item file="Turcja.png" />
			<item file="Szwecja.png" />
			<item file="Austria.png" />
			<item file="Szwajcaria.png" />
			<item file="Słowacja.png" />
			<item file="Rosja.png" />
			<item file="Portugalia.png" />
			<item file="Norwegia.png" />
			<item file="Hiszpania.png" />
			<item file="Grecja.png" />
			<item file="Francja.png" />
			<item file="Albania.png" />
			<item file="Czechy.png" />
		</category>
		
		<!-- category 2 -->
		<category id="Additional test">
			<item file="test_2.png" />
			<item file="test_3.png" />
			<item file="test_1.png" />
			<item file="test_4.png" />
		</category>
	</content>
</items>