Cannot remove a website in Safari on MacOS Ventura

I am running MacOS Ventura 13.7.2, Safari 18.2, on an iMac 2017.

There is one website, cargurus.com, which I have not visited for years, that I cannot remove in Safari --> Settings --> Websites. It shows under all functions (Reader, Autoplay, etc) except Contact Blockers and Notifications.

I went to History --> Clear History --> Clear All

I went to Settings --> Privacy --> Manage Website Data and removed all data. Did not even find any cargurus-labeled items there.

I rebooted in safe mode and repeated the above.

I then followed advice on this forum and went to Finder --> Go (option key) --> Library --> Safari and removed the Databases folder and cleared the Local Storage folder (had no cargurus-labeled items).

Rebooted normally, restarted Safari --> Settings --> Websites, and cargurus.com is still there exactly as before. In most functions under Websites the Remove selection is grayed out, and in those where it is available it does not remove the website when clicked, only switches permissions from Deny to Allow...

I know, I am writing this note in Firefox and can continue to use it fine, but it irks me that native Apple software is malfunctioning on a Mac.

Would appreciate any new ideas how to fix this.

Thanks!