Preview Inconsistencies in Captivate 2017

Using Captivate 2017 for a responsive design project, I have noticed inconsistencies when viewing the e-learning in  Preview mode. I have experienced things like missing buttons and graphics (PNG files) that are fuzzy. These occurrences seem to happen more frequently when I make the screen size small but it happens when the screen is enlarged, too. These occurrences happen seemingly at random.

Does anyone have any ideas why this is happening and if there is something that can be done to prevent or minimize the strange Captivate behavior?

Thank you.