Thank you! No more frustration when uploading!
I've got rid (almost) of the piiiii in a similar project adding an electrolytic capacitor in the input (+ and - terminals) of the bluetooth module. A 470uF electrolytic capacitor removes some noise, but a 1000uF or 2000uF was better in my project. So, I think you could try values between 470uF and 2000uF. I'm not an expert, but suspect that low noise to be radio waves propagated to input wires as when I increased the volume the noise also raised.