No sync with the phone possible

For accuracy, I can not say anything because my Fitbit may not be with my current mobile phone link (Nexus 4 with Lollipop). The support forum is full of Fitbit with exactly this problem of Fitbit not have a reaction (and yes, I have all indicated Troubleshooting versions tried). With an old Nexus 4 with Kitkat the sync worked. But according to forum, it seems simple matter of luck whether his Fitbit synct with his device and it is not dependent on the device / version.
Now have the written support, hope an early reply, otherwise the unit returns.