Solved! Laptop overheating when idle and plugged in

[Hesparides]

So I'm having this problem with my laptop (Eluktronics Mech-15 G2R)
I use my laptop plugged in 99% of the time, so it's not a battery charging overheating thing.
When I unplug the laptop, the temperature drops to 45C which keeps the fans inactive. However, when I plug it in the temp goes up to 60C ish and the fans kick in. I have some control of the fans so I can manage to keep them on the lowest speed.
I have checked the power settings and this happens even when the maximum and minimum processor states are the same when plugged in and when on battery (both at 70% and 0% respectively currently). Same with system cooling policy, all set to passive. All of the power options for the plan settings are the same when plugged in as when on battery. The plan is balanced and the slider is set to Better Battery.

The CPU activity, frequency, core count and TDP seems the same as you can see in the graph (left of the white bar is battery, right plugged in).
CPU is undervolted 130mV.
I just want to be able to use the machine plugged in without hearing the fan as when it happens on battery. How can I solve this?

 

[Manoj Shukla]

If it is overheating even when idle, it is because the air cooling system is thoroughly plugged with dust and lint, and there is minimal or no air moving through it, regardless of whether the fan is running fast or slow.
Consistent CPU load can lead to your laptop overheating when charging, as it causes heat buildup forcing the fans to run continuously to maintain operating temperatures. This heat can be caused by corrupt software or malware, which consume CPU time between 1 and 100 percent of the CPU

 

[Hesparides]

As I stated, the laptop overheating when charging was not the issue here because it is always plugged in.
I should have added that there wasn't too much dust.
Malware would've been a good guess. I found the problem and in the end it was software related: Nvidia RTX Voice. Apparently, it was filtering the noise with the GPU at all times, causing a higher temperature in the system.
Uninstalling it solved the issue (although, closing it was also solving it). It's a shame because it worked so well.

 

[RolandJS]

I add: always using an external USB cooling assembly (one giant fan or twin fans).