The first project I built was Nervous bird because it was the most simple.
Initially when I connected it to an android mobile phone, (and selected Nervous Bird) when I pressed turn left or right it would "slowly" turn in the correct direction. When I selected forward or reverse it would not move forward or reverse.
I installed the latest version of mBlock and updated the firmware. Now it won't turn left or right when connected to a mobile phone !!
The bot has new Energizer batteries. I tried on two different mobile phones and the same result (phones were different manufactures and different versions of android but both are above ver 5.0).
When I selected the standard ranger and picked up the bot and pressed forward both wheels turned forward in the correct direction. All directions seemed to work ok.. it is as if only Nervous Bird does not work.