Failed to work with SplashID

I just upgraded to High Sierra from Sierra and discovered my SplashID failed to sync the data with my mobile phone. Both my iMac and mobile phone are on the same wifi network. However iMac name cannot be discovered by the mobile phone and sync failed to operate. In the past I have been used it successfully for a couple of years on synchronisation. What did the High Sierra change to possibly cause this failure? Appreciate any suggestion to diagnostic this issue.