When entering a single character into the transaction item number, nothing is entered in the field and the drop-down list does not appear.
For example, if you wanted to enter "widget" in the item name of the invoice form, you begin to type "w". However, the list of items beginning with the letter w do not appear in the drop-down list.
This could be caused by damage to your item list.
Merge the first item of the letter you are trying to use. You may have to merge other list entries to completely resolve the issue.
If the issue persists, troubleshoot for data damage.