Built Form On Top Of Table - Use Combo Box To Update Value On Form

I have a table called input and a "form" input made on top of that same table. When I input the data on the form it updates properly no issues.

I have another table main. i update the vendor name using combo box from main.

It works like that.

SELECT main.[Vendor Number], main.[Vendor Name]
FROM main;

And I update the vendor name using control source =vendorname.column(1)

I have even achieved the same thing using DlookUp .

The problem is that it saves on the Form but the data from Dlookup or from comboBox updates for "Vendoe Nmae" is not saved in input table.