In our previous post concerning WCAG 3.2.1 On Focus, we discussed why you should avoid unexpected changes of context. A change in setting refers to the act of inputting data to a component, such as a checklist or text field. Just as a change in focus to a user interface component shouldn't result in a change of context, a change in setting should likewise not result in a change.
Let's say you're filling out a survey online. A change in setting, in such a situation, could mean entering text into a field, selecting a checkbox, or picking an option from a list control.
Note that selecting a button, tab, or link would not count as a change in setting. Such actions are typically understood as "activating" a control, so a change of context would be an appropriate result.
Users experiencing low or no vision may not be able to detect an unexpected change of context. For this reason, it would be a good practice to go through your site and ensure that no components would trigger a change of context as a result of its settings being altered.