DC to DC Buck Converter

This PCB was designed to take a 12V input from a DC barrel jack and output 9V. This PCB utilizes the LM2596T-ADJ IC to convert 12V to 9V using a feedback resistor pair of 10K and 1.75K. In the first design I mistakenly forgot to add vias to connect ground traces to the bottom ground plane. This caused ground to read as 4.9V and the board to not work as designed. The new design has vias to connect to the ground plane and the PCB works as designed outputing 9V.