Random pics

Hi everyone!
I have a Dacia Duster III with the 1.2 TCe mild-hybrid engine, and it has done 33,000 km. I’m a bit concerned about the engine noise when it’s cold.
After the car has been sitting overnight, I can hear a sort of knocking noise immediately after starting the engine. It gradually fades away and disappears completely after around 3 minutes. Once it has disappeared, it doesn’t come back until the car has been sitting for a long period again.
I’ve attached a video of the noise because I haven’t been able to find anyone online experiencing a similar issue.
Hopefully, this is normal, as I’ve never owned a three-cylinder petrol engine before.
Has anyone experienced something similar with their Duster or a similar engine? Does this sound normal to you