Wanted to consult yall on tis white oak near our shed. It bas put out great canopies and is a good straight tree, but ive noticed a few branches this year dying off and fungal spots forming. Today after parking the dump cart, i noticed this at the base of the trunk. I am in western Pa, and lately we have been getting hammered with rain. This is on the shade side shaded from white pine. Part of me wants this to just be powdery mildew but im also not sure if its Armillaria fungus. Hate to lose this tree over it. Posted a few photos and could certainly take a few more if needed. Any info is greatly appreciated!