Stegastes adustus has a round dorsal and anal fin, not to mention a distinguishable pattern of scales on the sides. May I suggest looking into young Acanthochromis polyacanthus or Chromis chromis?
The facility listed both Acanthochromis polyacanthus and Stegastes adustus in their 2020 inventory so it is more probable that it is the former. A bit of a shame but still a new species for my files. I'll amend the title of this photo.
