It seems that in firmware 6.42 public and 6.48 beta for XF - support for velocidrone mobile has been regressed.
If you are using this version of firmware then no stick data will be sent from your controller to velocidrone mobile.
We have reported this to Team Black Sheep for resolution. In the meantime users wishing to use TBS transmitters over wi-fi with VelociDrone Mobile must use firmware 6.31 or 6.36 for XF.