I found another thread on this indicating that a recent update fixed the issue, but it has not worked for me. The app worked fine for the longest time but today I saw a notice that my subscription was "canceled", which I knew was not accurate but when I tried to sign in I got a server certificate error. I cleared the app cache and data but still could not sign in. I then cleared cache and data again and uninstalled the app and rebooted. I then reinstalled Norton 360 and tried to sign in but I get the same error and when I tap the OK button the app closes. I am on the latest version of Android 13 if this helps and I attached a screenshot of the message I am getting.
I see your ad blocker seems to be involved here. If it did not block your Norton logins before you have been lucky. On PC's, ad blockers usually interfere with Norton web site functions such as signing in and web page redirects. You should be able to turn off the ad blocker functions for Norton pages.
Thanks for posting back with the solution.
I got it to work. Apparently the ad blocking service that I have used for years has suddenly interfered with the Norton sign in. I've never had to turn it off in order to sign in to anything before.
The phone is a Oneplus 8 Pro. I had Norton working until just recently and the only thing I can think is maybe the most recent Android update I got broke something.
I checked the settings you recommended and adjusted them as needed but it made no difference, I still got the same message.
What device are you using?
Check in Android Settings for any battery optimisations. Be sure they are turned off for Norton 360. Also check that in Settings > Accessibility > Installed Services. Be sure that Norton 360 Service is turned on.