When I run a scan with axe-core DevTools on a page containing an accordion made with your widget, I get a critical error indicating that for the element with a 'tablist' role "Element has children which are not allowed: [role=tabpanel]". The ARIA Authoring Practices Guide (APG) examples at https://www.w3.org/WAI/ARIA/apg/patterns/accordion/examples/accordion/ seems to show accordions shouldn't use tab roles at all.
When I run a scan with axe-core DevTools on a page containing an accordion made with your widget, I get a critical error indicating that for the element with a 'tablist' role "Element has children which are not allowed: [role=tabpanel]". The ARIA Authoring Practices Guide (APG) examples at https://www.w3.org/WAI/ARIA/apg/patterns/accordion/examples/accordion/ seems to show accordions shouldn't use tab roles at all.