Vampires should not emerge from dark areas during daylight, correct?
And if they do, they are supposed to take sun damage?
The vampires that sometimes appear under the secret door of the ruined tower in the Narrow Passage on the way to Midway take sun damage only in transitions. In the latter they emit wisps of smoke and become barely injured, but start regenerating once they leave the transition. They also pursue aggressively, going as far as the dock in Midway, in broad daylight.
The first time this happened it was raining, but the second time it was clear.