Ask for the agent's reference and handover record tied to your crate mark. The carrier label may cover a later leg, but that explanation still needs evidence of the earlier handover.
Give it the seller's crate mark and order reference as well. Different reference systems could explain the failed search, though they do not establish that collection occurred.
Then keep the location unconfirmed. A recognised booking narrows the enquiry, but it does not yet tell your installation team where the FR5 package is.