Norton 360 DeLuxe app is installed on my Samsung A21 phone & I have the "key" symbol showing but I cannot turn on VPN manually because the app tells me my connection is secure and the VPN on/off buttons are greyed out. The remainder of the services appear to work OK
I can confirm your findings and will escalate this thread to report the issue to the appropriate team.
My 360 version is 5.70.0.230922006