Creating pivot table from multiple ranges (sheets)

Hello everyone,
i have an issue while creating a pivot table.
My excel file consists of 30 sheets where there are a table in each of them. I need to create a pivot from multiple ranges (i am using alt+d+p), but when it is created from multiple sheets, data gets scrambled. What could i be doing wrong?

Please find an example attached. sheet "Merged data" contains information from three separate sheets, from that i can create the pivot i need, which is in "Correct pivot" sheet. Sheet "Incorrect pivot" contains table that is created using alt+d+p, from multiple ranges.

I would really appreciate your help, thank you.