I was able to replicate this loop by choosing "Visit all" in the Investment income section.
You can break out of this loop by clicking on Wages and Income in the upper left corner after you have entered all of your information for this section. Next choose, "I'll choose what I work on," the on the right.
You can then proceed to the next section, Retirement Income by scrolling down to it and selecting Visit all, or picking a specific topic.