Hi Mahmoud,
Interesting. Sounds like there might be something wrong with that one motor. We had a similar issue occur here in this thread: https://discuss.bluerobotics.com/t/t100-blue-esc-init-issue/
The shocking issue is definitely not good. That sounds like your 48V power source might be making it into the water somehow. That’s definitely a strange issue. Which bolts on the motor are you talking about? Is it the bolts that hold the BlueESC to the rest of the thruster?
Best,
Rusty