Ideas are evaluated inside a social field. Credibility, liking, and hierarchy change how carefully people listen and how generously they interpret ambiguity.
This is not always conscious bias. Attention is scarce. High-status speakers often receive more of it by default — so their framing gets a second of grace yours did not.
Useful noticing: Was the idea rejected, or was the speaker discounted? Those are different problems with different responses.
You can attach your idea to clearer evidence, find an ally who can restate it, or wait for a structural moment when the room needs what you already offered.