What computer operating system? What specific Movie Menu?
What did you create DVD-VIDEO standard or widescreen on DVD disc or AVCHD on DVD disc? NTSC or PAL?
What did you use for playback of the ISO file...or are you referring to the playback of the DVD disc to which the ISO was applied?
What video card/graphics card does your computer use? If not Intel HD Graphics 2000 or newer, then please disable that preference in Edit Menu/Preferences/General to determine if that makes a difference in the outcome.
Based on your details, I will do some road testing on this in the morning morning.
To be continued....