How can I see the reversed card at random?

[abdo]

Please see:

Randomize card type shown first, for the same note

IIRC, the sibling cards are given the same due number if they are repositioned randomly, as Anki tries to introduce cards in template order. The reason it does this is that often one card is easier than the other - it’s easier to recognize a word in a foreign language than it is to produce it for example. But if you want a fully random order, you can accomplish that with a filtered deck.