Graphics Display bottom third missing

I use a Database APP to track some on-line activity. There is an option to show a Value by time cumulative graph. When it is displayed the bottom third (approximately) does not display on the screen or print. I chatted back and forth with the support people at the App Developer and they found nothing wrong. I ran the app on my wife’s laptop and it worked fine. This App has nothing to do with Microsoft Office. Next, I tried different Windows 10 settings but could not find anything to change. I have placed questions in Google and found nothing. I have thoroughly checked my hardware settings as my HP Desktop is not supported any longer. All my other apps display properly. So why does one App on one computer not display properly?