Hello. I've just gotten into weight painting and I've come across some problems.
First, there have been weight changes happening without my knowledge. In one instance, my finger joints have weight assigned to the chest and pelvis region of my character. This occurred before I even started to edit the weight on the fingers. In another instance, where I've deleted non-deformer history and binded a fresh new skin, the fingers initially had no weight on them until I decided to work on the spine joints and out of no where, the fingers have weight on them in the chest area as I switch to the finger joints.
Second, when I try to clear some of these extraneous weights (via paintbrush or flooding vertices), once I switch to a new joint and switch back to the same joint I had just made changes to, the weights stay the same as before and they have become impossible to remove.
How do I fix these issues? Also, what would be an ideal workflow for weight painting in Maya so that I make sure I don't run into issues like these?