auspost and usps both don’t have my parcel and shows different updates

hi guys,

I contacted auspost bc my parcel was shipped via usps on dec 3 and on there it said it arrived Melbourne on the 5th of dec, but when I contacted auspost they said it hasn't even arrived here? i know its probably a small thing but the value was $900 so im just a bit tense. Does anyone know where the package might be if it's not in the states or in aus? has it been shipped out yet even? and will I know if it's been caught up in customs? im just very confused and I would really appreciate some help!