@Richard_Hadiputra I fixed your posted code formatting as required for forum viewing.
As for your issues…
All are generally related to a Servo Library conflict… On UNO It blocks PWM on pin 9 & 10
I have also noticed (at least on Arduinos) that the servo library doesn’t play nicely with SimpleTimer. Can cause servo jittering, and now that that BlynkTimer is built in it appears that the jittering can happen even without a timer defined.
I have found it best to use servo detach() when not actually moving the servo around.
Hard to say whether Bluetooth is also adding to the fun… it is still in beta and I have noticed it can cause (or at least reveal) additional timing issues with delayed reactions to app commands and some PWM inaccuracies.