Hi Paride,
Can you please send this video to otoy?
Octane has hard time rendering and denoising moving specular materials that have some roughness or bump.
In the video you can see once the car starts slightly moving (can barely see it at first) specular material of the garbage truck starts having chaotic noise and denoiser doesn't help at all.
There is just too much noise for animated objects that have specular materials. They definitely need to come up with a better solution. i've never seen CPU renderer or bucket renderer do this. After they do rendering of a specular material you'll never see jittering noise on specular materials.
Thanks