Textboxes showing up when you delete objects in a row like that seems like that is normal behavior for Report Builder - TextBox8 is not in the “Standard SSRS” version of the report.
PS: Our modified ARForm hides R405 unless it is trying to show some backorder. The KitFlag check is part of Standard by the way:
Hidden = (UCase(Fields!OrderLine_KitFlag.Value) = “C”) OR (Fields!Calc_BackOrdQty.Value = 0)
I’m not sure how often our people use Mass Print Invoices, but I’m also not aware of issues.