I have installed the Norton 360 app on my Samsung Galaxy A34 5G (Android): I enabled the Safe Web feature on Chrome and on the Internet app on the phone settings: when the results of a Google search show up on screen, each site should have, next to its address, a sign in green (safe), orange (attention), or red (unsafe), according to the safety of the site, but nothing shows up. The settings seem to be all Ok. Any thoughs on why it is not working properly?
On my Chrome browser in Android I use the search engine 'search.norton.com' and (as described by OP)
The OP is not using, or did not mention using the Norton Safe Search web site for searches. They are using Google searches. They do not get the green check marks on mobile devices.
On my Chrome browser in Android I use the search engine 'search.norton.com' and (as described by OP) the results should have a sign next to it (green/orange/red). Since this morning these signs haven't been showing up anymore.
The only thing that changed on my phones (it happens on all my phones) is that a new version of Google Play System updates was installed this morning.
Addition: on my iOS/iPadOS devices it still works flawlessly.
The Safe Web feature of the Mobile Norton 360 products does not have all the features of the PC versions. It does not have the search notifications in Chrome on the mobile versions. So there is nothing wrong with your installation. Safe Web will still pop up a warning if you tap on a result that is deemed dangerous, so you still have the same protection against malicious web sites.