Help with my arduino and hc06 (Android)

Hello, it is now several days that I try without success to control a simple servo motor thanks to the application blynk, without success.
I use an arduino uno and module hc 06, on simple example, the communication works sometimes, but many instructions are lost (example: my led remains alumé)
on the serial monitor, I often read: packet too big.
please help. thanks a lot