Laptop Display flickering at 144 hz but stable at 60 hz.

[PolluxBloom]

I have been using my HP Pavilion Gaming - 15-ec1052ax gaming laptop for half a year now. I use my laptop everyday extensively for work, multimedia and gaming. Everything was buttery smooth up until the past two days where I see my display flickering and freezing especially with mouse clicks and movements. Also i see bunch of horizontal line flickering at the top of my screen. 

Magically, when I turn down the refresh rate of my display to 60Hz from 144 Hz, the flickering kind of stops.

But I guess there is no point in using 60hz refresh rate when I paid more for a 144hz display. hope you all agree that.  

I have tried uninstalling and re-installing the graphics driver, did not help.

I also tried resetting my PC , that also did not help. 
I am sure there no Incompatible app that is causing this issue, because the issue persisted after I reset my PC and removed everything. 

I doubt if this is a hardware issue because the display runs fine on BIOS and also in 60Hz.

I am really feeling helpless now and looking forward to this community to show me a way to get it fixed. 

I beg for your help!!!!!!!!!!!

[WAWood]

@PolluxBloom 

This is almost certainly a hardware issue -- despite your denying that -- as it only happens when you change the refresh rate -- and is a hardware change, not software.  There is no way to fix that other than to replace the screen.

[PolluxBloom]

.@WAWood

May I know is my display broken or some issue with other hardware which influences the display?

I am confused if it is a hardware issue because the BIOS screen is not flickering.