That’s expected behavior — Excel doesn’t allow inserting rows inside a protected table, even if the table cells are unlocked and “Insert rows” is checked.

Workarounds:

1. Unprotect → Add row → Reprotect via VBA or manually.

2. Use a data entry form that temporarily unprotects the sheet, adds a row, then protects it again.

3. Or move the table to an unprotected area and lock only the rest of the sheet.

Excel’s “Insert rows” permission only applies to rows outside structured tables, not within them.