Doesn’t fox refer to anyone to the left of the American center as liberal?

Yes, they do… but this doesn’t change the fact that Fox itself peddles liberalism - ie, capitalism. That is, when it’s not peddling outright fascism - liberalism’s status quo-sustaining alter-ego.

I was thinking it wouldn’t make sense to call socialists

No, it doesn’t make sense to call people such as socialists - who want to dismantle all aspects of liberalism (and with it, fascism) - “liberals.”