  We present results from a 3.25 kg-day target exposure of two silicon
charge-coupled devices (CCDs), each with 24 megapixels and skipper readout,
deployed in the DAMIC setup at SNOLAB. With a reduction in pixel readout noise
of a factor of 10 relative to the previous detector, we investigate the excess
population of low-energy events in the CCD bulk previously observed above
expected backgrounds. We address the dominant systematic uncertainty of the
previous analysis through a depth fiducialization designed to reject surface
backgrounds on the CCDs. The measured bulk ionization spectrum confirms the
presence of an excess population of low-energy events in the CCD target with
characteristic rate of ${\sim}7$ events per kg-day and electron-equivalent
energies of ${\sim}80~$eV, whose origin remains unknown.
