The reasoning about non-neutrality is that a tree has captured some carbon (its growth), then we burn it and release that carbon back into the atmosphere (1:1 equality).
However, anything on top of that (production of pellets, transportation, retailing) takes significant carbon, too.
Solar panels don’t take carbon from the air, and we don’t burn solar panels. We do manufacture, transport and retail them, though. So yeah, solar capture is non-neutral.
The merits of one are independent of the other. Neither of which are carbon neutral. Last point, some might argue that solar panels reduce the carbon needed to combust; it’s hard to see that as carbon neutrality, that’s a broken argument. But, I’m not sure who’s making that point.
Wood is the fuel, so to power a wood stove you need to constantly be moving it to its ultimate destination.
(Unless, of course, the pellets take more energy to produce than they produce themselves after burning and conversion... but that just makes them inefficient under any energy market mix, not CO2-producing under any mix.)