You did exactly the right thing — that is a textbook version of the classic remote-rental scam, and the "conveniently abroad, can't meet in person, needs money before you can view it" combination is the giveaway every time. Real landlords and agencies overwhelmingly want to show the place before any money changes hands; urgency to skip that step is the red flag, not the ask for a deposit itself.
Good instinct trusting the "something felt off" — that's usually right.