Probably has an easy answer, but I can't figure out why an icon value retains its value of 10 despite my changing it to 1. It even shows both values in the value setting window. Where is this 10 value coming from? How do I delete it or change it to 1? Thanks!

That icon counter takes into account all columns in the 'current folder and its subfolders'
The two values for the + icon mean that there is at least one column in that selection of columns that has a value of 1 and at least one other that has a value of 10.
You are focussed on the 'From 0 to 10 (icon values)' grade types which is correct but there is at least a different grade type in that selection of columns that has a value of 1 for the + icon.

Yes, it turned out that one of the columns in that folder DID have a value of 10. Changing it to 1 fixed the problem. Thanks!