WD warranty registration

Hi, today I received my two WD 2tb red drives for my Readynas 314. These were both retail packs ordered from Amazon UK. All arrived brand new and sealed. I registered these online with you WD via their site. Later when I checked on the status of the warranties, one has the full three year warranty, one states out of region limited warranty???
Both were also registered within 5 minutes of each other yet the warranties vary by lots of days difference cover. Some thing seems very odd here

Hello,

I recommend you contact WD support so they can assist you updating the warranty on your drive,
They probably will need a proof of purchase so they can update the warranty from the purchase date.

https://support.wdc.com/support/case.aspx?lang=en