ASUS - ZenTalk

System: vivobook laptop
Battery or AC: Battery and AC
Model: x512da zyzen 3500u
Frequency of occurrence: occasionally after few hours of usage.
Reset OS: yes clean installed windows 10.
Screenshot or video:
========================
Detailed description：
After few hours of usage laptop slows down drastically and stops charging.
Occurring since few months but i recently noticed it closely as one day my laptop was at about 17% battery and was slow i thought it might be due to low battery i plugged the charger and left, even after an hour, it was slow and and then i noticed it's still at 17%. battery charging red light is their but its not showing charging in windows.
I tried to change power setting and put the full capacity option in my asus battery option. Even after that issue still their.
After that i tried to power off it by long pressing the power button for few seconds and turn it on and everything went back normal and battery started charging again.
Again after few hours battery stopped charging and laptop was slow again. I thought it was due to windows issue and tried on fedora linux but the issue was still their and battery was not charging their too.
In linux i noticed that the cpu frequency was only 400mhz, even at lower temperature it was showing as termal throttling.
Have raised a service request and service center said their is no hardware issue after checking my system, they don't fully understand the issue and since it's occasional i was not able reproduce the issue to show it to them at technitian visit.
My laptop usage is not very intense, web browsing and web development.
To check the stability i tried to render a small 5min 1080p video in adobe premier pro and the cpu frequency was jumping between 0.4ghz to 1.3ghz and was not hitting the base 2.0ghz clearly their is some issue with the bios please check the issue and fix it asap.