this can happen to every building when spawning items only as proxy
as you see below, there no 100% chance to any of items. so in rare cases they can spawn no loot

<group name="Land_Mil_ContainerHabitat_Armory_Locked_Green_DE" lootmax="0">

<usage name="Military" />

<container name="lootFloor">

<category name="containers" />

<category name="clothes" />

<category name="weapons" />

<tag name="floor" />

<tag name="shelves" />

<tag name="ground" />

</container>

<dispatch dechance="0.5">

<proxy type="m14" pos="-0.520 0.85 0.87" rpy="0.0000 180.000000 90.000000" dechance="0.5" />

</dispatch>

<dispatch dechance="0.5">

<proxy type="m14" pos="1.0 0.75 0.308" rpy="90.000000 0.000000 -90.000000" dechance="0.5" />

</dispatch>

<dispatch dechance="0.5">

<proxy type="m14" pos="-0.255 0.85 0.87" rpy="0.0000 180.000000 90.000000" dechance="0.5" />

</dispatch>

<dispatch dechance="0.0">

<proxy type="SV98" pos=" 0.316 0.75 0.87" rpy="0.0000 180.000000 90.000000" dechance="0.0" />

</dispatch>

<dispatch dechance="0.0">

<proxy type="SV98" pos="1.0 0.75 0.855" rpy="90.000000 0.000000 -90.000000" dechance="0.0" />

</dispatch>

<dispatch dechance="0.0">

<proxy type="SV98" pos="1.0 0.75 0.035" rpy="90.000000 0.000000 -90.000000" dechance="0.0" />

</dispatch>

<dispatch dechance="0.0">

<proxy type="SV98" pos="1.0 0.75 -0.243" rpy="90.000000 0.000000 -90.000000" dechance="0.0" />

</dispatch>

<dispatch dechance="0.75">

<proxy type="AKM" pos="-0.781 0.75 0.87" rpy="0.0000 180.000000 90.000000" dechance="0.5" />

</dispatch>

<dispatch dechance="0.5">

<proxy type="AKM" pos="0.02 0.75 0.87" rpy="0.0000 180.000000 90.000000" dechance="0.5" />

</dispatch>

<dispatch dechance="0.5">

<proxy type="AKM" pos=" 0.584 0.75 0.87" rpy="0.0000 180.000000 90.000000" dechance="0.5" />

</dispatch>

<dispatch dechance="0.5">

<proxy type="AKM" pos="1.0 0.75 0.579" rpy="90.000000 0.000000 -90.000000" dechance="0.5" />

</dispatch>

<dispatch dechance="0.5">

<proxy type="AKM" pos="1.0 0.75 -0.505" rpy="90.000000 0.000000 -90.000000" dechance="0.5" />

</dispatch>

</group>

same for burning tirepile spawned via static spawner in events.xml