Hmmm … it appears one of the SOHO HMI continuum images from 8-21 (left)caught the sun in a partial eclipse(? from a different vantage point). The radius of curvature of the defect matches that of the moon based on an image (right) taken at the start of the eclipse.
EDIT: However I just realized SOHO orbits the sun at L1 and so is far outside of the moon's orbit and so the moon cannot pass between SOHO's instruments and the sun!!! Guess I'm not sure now what that defect is after all.