I have an exposed filter that generate a table style view.
Exposed filter is set to "contains any word" operator and the view table style in "grouping field: customer".

Now, if i search only one client i can export table data in xls file successfully, but if i filter two clients (for compare their behaviour) having as result two separated tables, export fails because the xls file is completely empty.

Why this behaviour? It's a bug or something else ?
Thanks to all