Positive vs. negative heat of solution confusion
The heat of solution (aka enthalpy of the solution and $\Delta\mathrm{H}_{\text{sol}}$) is negative if heat is released. The reason is that energy is leaving the system. The reason you got two different answers is that the sources you referenced are describing two different things. The $\Delta\mathrm{H}_{\text{sol}}$ is positive (endothermic) when dissolved in water, but Erythritol is commonly combined with Inulin which produces an exothermic reaction (cancelling out the cooling effect of the Erythritol).