Why is my project unknown?

It's because the project isn't verified. You need to have your project verified by a member of our team for it to show up more clearly for buyers. This can be done by following this article: Verify your Project

If it’s unknown and hasn’t been verified yet you need to untick 'Verified Only' in the filters and you will see it come up. Unless the buyer has it unticked as well they will not see it.