Why am I not seeing all Customer/Supplier Terms?
Under (Sales > Customers > Details tab) and (Purch > Suppliers > Details tab), whenever the '...' button is clicked to launch a look-up for other payment terms, the look-up will be pre-populated with a search term. So, you won't automatically see the other terms. You first need to click the 'X' button that is beside the search field so that the search field is cleared, then the others should appear.