They are actually called something else.
It's happened with all my cats apart from my first - the late, great Bertie.
So my current cats 'real' names are: William, ( extrovert black boy ) Dora, ( dainty princess blacky browny half Burmese) Susie, ( feisty disabled tor tie and white) and Oliver Rabbit.( gentle elderly tabby failed foster cat.
Why does this happen? What are your cats' other names?