Need suggestion about copywriting freelance job

Hi,
I have been working with this client since Jan, and he was really good with payments like as I complete my work, he paid me in less than 2 min - always that fast.
But now he got silent. He is reading my messages but didn't pay me last month's invoice and its already 11th of this month. Should I continue to work, or ask him to pay me first?
He may have some financial issues, but its already almost 2 weeks.
Should I remind him about the invoice?

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