If you insert a number of cells and shift down, you are only moving the
cells in those columns. This shifts cells that were in the hidden rows
down one row while leaving the other hidden cells unchanged.

If you insert an entire row, the hidden rows will move and their
contents will remain hidden. You could do something like

Worksheets("Sheet1").Rows(12).Insert

to insert a row before row 12, then copy and paste your hidden
information into the new row 12.