I think the border for the card Spikeridged Steed is wrong on the Website.
The card is defined as Paladin and is available in the Paladin class using the filters.
It was always a Paladin card. But the border matches the Warlock class.
Please have a look at your website:
https://playhearthstone.com/en-us/cards/41864-spikeridged-steed?class=paladin&set=journey-to-ungoro