[Aaron Lieb]

Todd,
I did find this in the help when I was trying to fix this issue.
This seems like it would help if everything were operating “normally”
I think my problem stepped outside of the realm of normal.

When I went to the column selection – “Source Name” was grayed out
as normal, but also unchecked (not normal).
The function for switching between
Source Name and Layer Name also ceased to work – even with the
prescribed hot key. See if you can recreate this situation. How does
one uncheck a grayed out option? (grayed out to prevent you from
unchecking it)