I have enabled this setting. It worked previously but has recently stopped working on Moodle 3.1.5+ (Build: 20170316) . Are there any other settings that need to be adjusted for this to work?
General developer forum
Prevent multiple Login with Same ID
Are you sure about that?
Don't you use an SSO method? Which authentication method do you use?
Can you describe exactly what you do, with details on your Moodle (version and authentication) and how to replicate that.
If necessary, please fill a tracker issue, with lots of details.