I don't see that you did share a screenshot.
Are you share you have made the plot window an appropriate size ?
You can avoid the plot window and write to disk, and then open in an image editor or what have you from there.
I believe @ nirgrahamuk means that the plot panel is too small in RStudio. You can enlarge it by dragging on the left edge of the panel or the top edge. I have had the same problem but can not reproduce it to file a report.