Not all fields and buttons displayed correctly

Not all fields and buttons displayed correctly

1. When selecting Add, Cancel and Save buttons should display directly below the newly populated input fields - above any existing invoice info (as on MxConnect) - Complete
2. Complete button should be displayed at the bottom of the section - next to Add, as illustrated in example on Jira (not currently on MxConnect) Jira Example
3. No special characters allowed in Description as in MxConnect - Complete
4. No Complete button displayed - Complete
5. (AC6) When the user navigates to the previous (closed) business period's Unpaid invoices (using the back arrow on the month date picker) the Edit and Delete buttons are disbaled for selection, but NOT greyed out as on MxConnect (to clearly guide the user that they are not open for selecttion) 
6. (AC6) Also when the user navigates to the previous (closed) business period's Unpaid invoices (using the back arrow on the month date picker) the Add button should not be displayed at all

 Issues 5 & 6