Expensive Amazon Package Marked Delivered but Not Found (CANADA)

I am dealing with a really weird Amazon delivery issue and wanted to see if anyone else has had this happen.

I ordered an electronic device that cost over $400 CAD. On Amazon , it says the package was delivered at around 3:53 PM, but there was no proof of delivery shown there.

The confusing part is that the carrier, UniUni, says it was delivered at around 11 AM and they attatched a photo of the item there. So now there are two different delivery times depending on which source I look at.

What makes this worse is that it was snowing in my area that day. The box itself was fully white from what it showed on UniUni, so even if it really was dropped off, it could have been completely covered by snow very quickly after the driver left.

Since the item was an electronic device, if it was left outside in heavy snow for hours, the snow have caused water damage and completely ruined the item.

Moreover, I had previously ordered another device worth a little over $300 CAD, and for that item they required a signature at the door. But for this order, which was even more expensive, apparently it was just left outside.

It also arrived 3 to 5 days earlier than expected. The last time I checked, which was around midnight on March 13, it still was not supposed to arrive that soon, and then somehow, later that same day, it was marked as delivered.

So overall, the red flags are:

• Amazon says it delivered around 3:53 PM
• UniUni says delivered around 11 AM
• No proper proof of delivery on Amazon
• Heavy snowfall could have buried the package
• Because it is electronic, water damage could have fully destroyed it
• An expensive electronic item was left outside with no signature
• Delivered much earlier than expected

Has anyone dealt with something like this before with Amazon or UniUni? What is the best way to handle it to make sure Amazon actually investigates properly?