The random “hey stranger” from your ex isn’t closure. It’s a free trial for a subscription you already cancelled.

A casual message from someone you have ended things with usually arrives because they are lonely for an evening, not because anything has been resolved. It reopens the feeling without reopening the situation, and then the quiet comes back and you are further behind than before. Wanting it to mean something is completely understandable, and separate from what it is.

Before you reply, ask honestly what you would want this to lead to. If the answer is something that is not on offer, let it sit unanswered. Nobody is obliged to reopen what they already closed.