If they're saying it's been delivered, ask for proof. As it's EVRI, it's usually a photograph taken by the driver. If they can't provide proof of delivery, raise an official complaint with them regarding a missing parcel.
'They've tried to deliver my package but there was an issue' will have been logged by the driver. But that clashes with Amazon saying it's been delivered.
Reasons it is missing include:
It's back in the warehouse, the driver took it, a member of the public took it, or it was delivered to another address.
You need proof of delivery as they say it's delivered. If not, a missing parcel complaint needs raising.
Any subsequent investigation should include a conversation with the driver concerned.