Safari ignoring my host file all of a sudden?

I'm a website developer and previously I would edit my hosts file to work on the site before the domain name was resolved because I didn't want it public.

This is how I would do it https://www.chriswrites.com/how-to-edit-the-hosts-file-on-the-mac/

Now it's worked perfectly for years up until my last build when a couple of days ago after I added the address it still goes to the old site??

Firefox is following the hosts file and I'm able to work on it that way but still what the heck is going on?

My desktop is up to date and am running Ventura 13.0.1

I've flushed the cache

Help!