Trouble Populating Adjacent Cells Using Drop Down Lists

Hi there!

I more or less have a very simple situation yet the resolution has been beyond difficult. On Sheet 1 of a workbook, I have two columns of data. Column A (rows 2-3112) are filled with part numbers (which include a hyphen) and Column B (rows 2-3112) are filled with part descriptions.

On Sheet 2 of the same workbook, in Column A I want to be able to select from a drop down list the part number. Once I select a part number, I want the adjacent cell in Column B to populate with the corresponding part description.

Data validation and drop down lists I've gotten down just fine, but I've tried everything from VLOOKUP, to INDEX, to INDEX-MATCH, etc. function to try and get Column B on Sheet 2 to populate with the description of the part number I select from the drop down list in Column A on Sheet 2.

The drop down list on Sheet 2 corresponds to Column A on Sheet 1.

I would really, reallly appreciate the help if anyone can. Thank you in advance!