Update on my slipping plug. I cleaned everything with alcohol and torqued it to 10nm. It's not slipping anymore. Well in place
However, I am getting a clunking noise from the hamdlebar from when I ride. It clunks when I go over bumps or when I sprint and rock the bar a bit more. I have disassembled everything many times, torqued the top bolt many times and also torqued the stem bolts to recommended 5NM.
When I rétorque everything, the sound goes away but quickly comes back, like if something loosens up, but there is no play that I can feel in the headset.
I am running out of ideas of what can cause the clunking noise. Any idea is more than welcome. I am getting crazy with that sound when riding.