It's just a text field.
Before having this problem, I had changed the query upon which the report is
based; that is, I changed the actual query, leaving the record source
property of the report untouched. Now it looks like it is refusing to update
the grouping combo box. I have tried changing the record source to other
things, and the grouping combo box updates accordingly, but when I change it
back, the fields listed are still those from the query before I changed it.
I thought about deleting the query and starting over or changing its name and
setting the record source property accordingly, but while I was fumbling
around, I tried setting the group level to an expression, i.e. the field on
the query I was trying to find. This seems to work. Would I have any reason
to think otherwise?