LOL, every Democrat will win Virginia against Trump: the margins may vary but the outcome will not.
In all likelihood, this poll sample is overly (moderate) Republican and as any GE campaign heats up, Bipartiden's favorables and appeal will get shredded, with those voters hunkering down where they always were going to be (with Trump).
After all, Virginia is basically the national capital of "economically conservative and socially liberal" and "I'm a very thoughtful and deliberate swing voter (not)".
You're right on this one.
At the moment something like that would not be surprising :
Biden vs Trump : Biden wins 53/45
Buttigieg vs Trump : Buttigieg wins 52/45
Warren vs Trump : Warren wins 51/46
Sanders vs Trump : Sanders 50/46