This is a bug, fixed in this commit but still present in the latest 5.3.2 build. The OnUpdateTransform function was being called every time the component’s transform changed and it was causing a refresh.
Unfortunately, the flickering issue is still present and I haven’t find a solution yet to fix it, I’m commenting here hoping for good news in a near future.
Edit: Nonsense update, changing the material of the cable from Opaque to Translucent and setting the opacity to 1 solved the flickering issue, I think this could be a bug in the render pipeline…