There was a small "..." icon to the right of the webpage address bar when clicked on resulted in a dropdown menu with the option to "Translate this page. This is no longer there. Is there a way to get it back?
It should still be there. It's there still in 18 (Safari 18) and Sequoia I use it all the time.
Try the View menu and see if translate is still there.
It's possible that your update means you've lost a language
Try going to Settings>general and check the language you want is still there.
Restart to force any change. Restart anyway if you haven't
I found a work around. In the Safari toolbar: View>Translation>Translate to English. Courisoulsy, on my iPad, when I click on the icon on the nightside of the address bar the option to translate to English drops down. But this does not happen on my MacBook Pro.