Is it possible you have two fields stacked on top of each other?
I just checked that and no, there is no other field on the Portal.
Thanks for the reply!
Try selecting it and ungrouping. It may be that you have grouped the field with another object--which would explain the greyed out options that you mention.
Yes, ungrouping did the trick. At some point it must have been grouped with something but I didn't think to check that.