Faulty adapter or something else? + Acer's service

About the issue, as soon as I connect the adapter into the laptop the laptop makes strange static/electrical sounds. After the adapter is connected, the charging status keeps toggling between charging and discharging status (I think it's called intermittent charging?), the pin is not loose because after about 2-3 mins the charging stabilizes and the noises stop, then if I disconnect the adapter and leave it for let's say 30-45mins allowing it to cool, it loses that stability and if the adapter is connected again, the laptop again starts to make those noises. Please help me understand this issue. I am so mad at myself for choosing acer predator(13500hx+4050) over lenovo loq(it had a better gpu aswell)this April, despite having read countless complaints about their service I went with the brand value of "predator" hoping i wouldn't have to go to their service centers any time soon since I have never had to do so with other electronic equipments I have had. Now I am not sure if the service will hold up to the reputation, they have somewhat lived up to it by replacing the fans without even connecting the adapter into the laptop even once!! They completely ignored the faulty adapter being a potential culprit even though I did explicitly mention this, now let's see what they do in the second meeting.