Attachments move to bottom of email after sending

Suddenly, in Apple Mail on my iMac attachments appear below the signature in my emails regardless of where I place them when I compose them. The "Edit > Attachments > Always insert attachments at end of message" is NOT checked. "Place signature above quoted text" is checked in the Signature Pref Tab, but attachments are obviously not quotes. Any ideas how I can get the attachments to stay where I want them to be?