This is definitely an important question to ask, but it’s impossible to prove that you’ve been copied. Maybe it’s a coincidence, maybe not. I’ve experienced the same myself, and it’s very frustrating. I’ve had too much integrity myself and have stopped many projects in the middle of it because I suddenly discovered someone else with the same idea. A few weeks ago I attended a webinar and learned about the book «steal like an artist». I’ll never want to copy someones art, but the same idea can be used without being called plagiarism. It’s a cruel creative world! Good luck! 😊