In our installation, we have one field configuration that applies to most screens. I wanted to have a slight twist on this config, and as I am new to field configurations, I thought I would start by copying the existing field configuraton so that my changes would not affect the existing settings.
That was a wrong assumption.
Basically, the only thing I wanted different for one of my projects was making Components a required field. So after opening my new field configuration and making sure it only applied to a screens in my project, I went back to the original and saw that the changes were reflected there as well! It was as if every change was global.
I do not understand what a field configuration is if the changes are not scoped to the field configuration, but is applied globally across all field configurations.