IDs used in ARIA and labels must be unique
As implied from their property name,
id values should be unique regardless to accessibility.
Aria attributes heavily rely on
ids to label elements, signify their linkages and convey the relationships between them.
How Users Are Affected
The duplication of
ids, especially when used with ARIA attributes, may cause screen readers and other
assistive technologies that depend on the accessibility tree, to parse and read elements incorrectly or ignore them at all.
WCAG Success criteria
This issue might cause elements to fail one or more of the following Success criteria:
4.1.1 Parsing (A)