Without the data set, it is difficult to say, but my guess is that R simply does not display data in the way you expect. It can be a real frustration.
[quote]Do you know other alternatives to str() or glimpse()
[/quote]
No, they are ways to view a data object. I do not think there is much else that supplies a visual summary.
I think the main thing is that it is not always possible to view an R object as easily as a text file or a spreadsheet.