Myoware muscle sensor doesnt work when powered by the computer .. please help

I am trying to use myoware on my bicep to control a servo motor
and to do that I need to determine the threshold value and that means I need to read the changing reading values of flexing my bicep muscle
the problem is I followed each step I could read very carefully and it doesn’t work
I tried many reading codes but nothing worked
I connected the myoware to Arduino and then connected Arduino to my computer and uploaded the reading sketch but nothing changes when I flex my bicep. I also noticed that the SIG led is not fading out and in when I power the Arduino from the computer but it did when I power the Arduino by an external battery, but that means myoware sensor doesn’t work when connected to the computer and I cant read its value then.
please help
I attached a pic of myoware connection to Arduino

Can't see the program code you used.

Did you Serial.print() the values you are receiving from the sensor?

paul

Just in case anyone else has this problem. The OP's issue was solved by unplugging his laptop's power cord and running it on its battery power. This seems to occur when user's do not employ USB isolation.

Which solution do you recommend for PCs powered by mains?

Use a USB isolator like this one from Adafruit

Although this issue usually only happens to laptops

AdvancerTechnologies:
Just in case anyone else has this problem. The OP’s issue was solved by unplugging his laptop’s power cord and running it on its battery power. This seems to occur when user’s do not employ USB isolation.

And what is your explanation of this phenomenon?