No, depends on the mobile phone (Bluetooth/Android version?). I also had problems in the past. I had to turn off the machine (not just switch it off!). With the new mobile phone it works perfectly so far.
The whole Bluetooth thing is actually of little use anyway (a few seconds), as you have to put a cup underneath. You can also start the coffee directly on the machine. It makes more sense to programme the four buttons on the machine according to your own needs...