Why does this dynamic happen to me often?

Guy expresses interest in me first >>> Tells me that he’s not interested in pursuing a relationship with me >>> I back off in an attempt to move on and protect my feelings >>> Guy insists on being or staying friends
Updates
10 mo
I also wanted to mention that the guy will continue to flirt with me in the event that I agree to be friends.
Why does this dynamic happen to me often?
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