Vectors importing to Animate as fuzzy bitmaps

I've got dozens of Illustrator files that have imported as expected into Animate. But one piece of art that I've used in five variants of the same art keeps coming into Animate as a bitmap, and a fuzzy one at that. The files contain gradient fills. I've created new files with the same sort of art and they come in fine. No, I'm not clicking the Convert to Bitmap box... What in the world has gotten me tangled up?