[role] values are not valid
Webflow uses ARIA in some elements, such as TABS and the Hamburger menu. You don't need to do anything, it works fine.
If you get this error, check Custom Code or Element Settings > Custom Attributes.
Google Lighthouse says
Users of screen readers and other assistive technologies need information about the behavior and purpose of controls on your web page. Native HTML controls like buttons and radio groups come with that information built in. For custom controls you create, however, you must provide the information with ARIA roles and attributes. (Learn more in the Introduction to ARIA.)The ARIA specification includes a defined set of roles. When the value for an element's role attribute doesn't match a role from the set, assistive technologies can't announce the element correctly or interact with it as the developer intended.