Hello,
1- Regarding the Menu related concern, you had added an extra Menu element in the Header on your Site without selecting Menu in it which is why it was showing that notice. So, we have removed that extra Menu element in your Header: https://snipboard.io/TeHrDJ.jpg
2- Regarding the backend Products layout disruption, it was happening due to a third party Plugin conflict. When we deactivated the “Rank Math SEO” plugin on your Site, the Products layout disruption at the backend was gone and then the Products were appearing fine.
So, it is a third party Plugin causing the conflict not an issue at the Theme end.
Best Regards
.
