480p is the highest resolution of a DVD. The maximum resolution a standard DVD is 720 pixels horizontally by 480 pixels vertically (720x480). This can be progressive scan or interlaced. What steps are you taking to burn the DVD, what exactly are you trying to burn? Is the video you are trying to burn in HD quality?
You might want to seek help from the NCH Tech Team here: https://www.nch.com.au/support/index.html