Under the Accessibility Final Checks I receive the Known Problem: Data table with more than one row/column of headers does not use id and headers attributes to identify cells.
Omni CMS Final Checks look over all the code on a page and detect accessibility issues that do not meet WCAG 2.0 (Level AA) standards. It has detected that the page contains
Unfortunately the WYSIWYG editor does not support a method of adding IDs and header attributes. Tables with more than one row/column of headers cannot be made accessible through the WYSIWYG. Replace the table with a snippet such as cards or columns to group data instead.