Intellij proxy tunneling authentication failure

I installed the plugin (SonarLint Intellij 4.1.1.3345) for but fail to connect to sonarQube server (https behind proxy).
Proxy settings are ok (clicking Check connection with the sonarQube server’s address gives me “Connection successful”).
However, when trying to connect to the sonarQube server with username/password (same one used successfully when connecting to sonarQube server from the browser) I am getting the error message:
Failed to connect to the server. Please check the configuration. Error: Fail to request https://.../sonarqube/api/system/status.
In the logs I see:
Caused by: java.io.IOException: Failed to authenticate with proxy at org.sonarsource.sonarlint.shaded.okhttp3.internal.connection.RealConnection.createTunnel(RealConnection.java:418)
I know about the restriction on Basic authentication for proxy tunneling after jdk 8u111, but I have already removed the restriction by setting the VM property -Djdk.http.auth.tunneling.disabledSchemes="" in idea64.exe.vmoptions (as well as that for the external jdk through net.properties).
I’ve left it at that for the time being as I’m not sure what to try next.