Can't assign a dollar amount to Unassigned Vendor in Cost Code setup

When we are setting up estimated cost in Cost Code Detail in Job Maintenance, we are almost never sure which vendor we are going to use and have always been able to assign a dollar value to "Original Estimate" for an Unassigned Vendor. If we tabbed past Vendor No. it would allow us to enter dollar values below. This week we all of a sudden can't tab past the Vendor No. field to assign enter a dollar amount. I found the Sage article that says:

  • If a subcontractor has not yet been selected for work related to the cost code, enter an unassigned vendor.

It says "Unassigned" next to Vendor No. but I still can't tab past that field or enter dollar values below. Anyone know how I can enter a dollar value for Original Estimate while leaving the Vendor as Unassigned?