PNG 234 KB used in In Design file export blurry to PDF

In Design beginner here. I am creating a print flyer and the PNG image within my file exports blurry to a PDF, while all else is hi-res. The PNG image is 234 KB. The document is letter style (W: 51p0, H: 66p0). Is there any way I can adjust the image or file to match the quality of the artwork within the file?

attached to show the image quality.

Thanks!