Brown spots on Cornus alba 'Aurea'

I looked it up and could only find references to anthracnose.  This is only about a dozen small spots over the entire plant so surely (hopefully?!) not something as serious as anthracnose?  Also it's C. alba 'Aurea' which isn't listed as particularly susceptible.  Any ideas anyone?  I don't want to lose it, it's beautiful and I only bought it 3 weeks ago.  Many thanks.