Apple Mail Folders Missing After Updating to MacOS Ventura 13.6.5
I have many mail folders in my Apple Mail. However, after updating to MacOS Ventura 13.6.5, they all disappeared. I could locate the mails in those folders when using search, but the folders are nowhere to be seen. How can I retrieve them? I suspect they could all have gone into this folder called "Import" under On My Mac but I urgently need all my folders back. Any advice here is greatly appreciated.
MacBook Pro 13″, macOS 13.6