I see something in the manjero .vbox file's disk keys in the XML.
The manjero guest has a snapshot. Here is the disk registry for the guest:
<MediaRegistry>
<HardDisks>
<HardDisk uuid="{1eae7798-c6ba-45af-9d3a-f35993216e4f}" location="manjaro-kde.vdi" format="VDI" type="Normal">
<HardDisk uuid="{8c2e89ee-380a-4b49-9e55-7c12691f5eaa}" location="Snapshots/{8c2e89ee-380a-4b49-9e55-7c12691f5eaa}.vdi" format="VDI"/>
</HardDisk>
</HardDisks>
Here is the current snapshot's disk attachment registry:
<StorageController name="IDE" type="PIIX4" PortCount="2" useHostIOCache="true" Bootable="true">
<AttachedDevice passthrough="false" type="DVD" hotpluggable="false" port="1" device="0"/>
</StorageController>
<StorageController name="SATA" type="AHCI" PortCount="1" useHostIOCache="false" Bootable="true" IDE0MasterEmulationPort="0" IDE0SlaveEmulationPort="1" IDE1MasterEmulationPort="2" IDE1SlaveEmulationPort="3">
<AttachedDevice type="HardDisk" hotpluggable="false" port="0" device="0">
<Image uuid="{1eae7798-c6ba-45af-9d3a-f35993216e4f}"/>
</AttachedDevice>
</StorageController>
Here is the original pre-snapshot disk attachment registry:
<StorageController name="IDE" type="PIIX4" PortCount="2" useHostIOCache="true" Bootable="true">
<AttachedDevice passthrough="false" type="DVD" hotpluggable="false" port="1" device="0"/>
</StorageController>
<StorageController name="SATA" type="AHCI" PortCount="2" useHostIOCache="false" Bootable="true" IDE0MasterEmulationPort="0" IDE0SlaveEmulationPort="1" IDE1MasterEmulationPort="2" IDE1SlaveEmulationPort="3">
<AttachedDevice type="HardDisk" hotpluggable="false" port="0" device="0">
<Image uuid="{8c2e89ee-380a-4b49-9e55-7c12691f5eaa}"/>
</AttachedDevice>
<AttachedDevice type="HardDisk" hotpluggable="false" port="1" device="0">
<Image uuid="{68875579-5923-4090-b612-f672cb93c5ff}"/>
</AttachedDevice>
</StorageController>
I may be reading this wrong but :
The UUID starting '1eae' appears to be the parent disk and the UUID starting '8c2e' appears to be the child disk.
The current snapshot has the parent disk loaded, and the original configuration has the child disk loaded. This seems backward to me.
I don't know how to fix this, but something seems wrong.