read multiple excel files - strange behaviour

Good morning,

I see a very strange behaviour in looping in sheets from an excel file (see attached). Excel file is very simple, three sheets, one column, 50rows first sheet, 50 the seconds and 25 the third, total 125 rows.

The loop returns 150 rows instead of 125 and in addition it seem repeating just the first sheet.

What I am doing wrong? Is this a bug?

test_fogli.xlsx