Signal Line Healing no longer works

Hi community,

I have Simulink 2016b in use and following problem, that i can't see the small blue suggestion lines if i track one block inline to another block. Is there any option i have disabled. Shortly after the initial installation this feature worked fine. In the help i only found a video of signal line healing, https://www.mathworks.com/videos/smart-signal-routing-70086.html, which explains the feature, but doesn't give an hint how to enable or disable this function.

Would be nice to get any help.

Thanks

Cheers