Q.White Web And/or Fungus Like Stuff Under Maple Tree Bark
I started to notice some white web or soft fungus type stuff around crevasses of my maple tree’s trunk bark. I didnt make much of it until I clipped off some of the bark, there was more of it, and then more bark came off. As seen in the second photo, all the bark down to the main trunk line came off. What is this? what can I do about it? The tree was in the basement all winter, with the basement kept at ~45% humidity. It is in a polyester type bag and was watered 1x week throughout the winter. The foliage came in strong for the spring and the leaves look normal. Thanks!

Certified GKH Gardening Expert
Until it fruits, or unless you see its spores or signs of what it is under a microscope, it will be difficult to say what it is. There are a number of fungi, both beneficial and non, that will grow on the tree. If it continues to grow normally, then it is likely a friend of the tree. If you notice problems, then suspect this as the problem first.
If you just want to do things in a way that is more preventative, you can try fungicides:
https://www.gardeningknowhow.com/garden-how-to/info/using-fungicides-in-garden.htm