Laptop display messing up

[princess-donut]

System Specs:

Hi, this is my Windows HP pavilion notebook (Model no. 15au116tx). It's 7 yrs old.  Windows 10 - 64  bit.  NVIDIA GeForce 940MX.  Intel (R) HD Graphics 620.

Issue:

Sometimes while using, abruptly, the screen content squishes up to the top half, and repeats. As you may be able to make out in the pic, the repetitions kind of overlap and are of different widths. Some stretched, and some squished width-wise. The display stays like this until I force restart.

This doesn't happen too frequently. Would have happened 20-30 times in the last year of moderate usage. Though I have noticed at times horizontal lines flickering randomly on the display. I feel around the halfway mark. This flickering is a little more frequent and is often a precursor to the display messing up.

What I have tried:

Here are some things I tried to diagnose the issue:

• Folding/Unfolding - I folded, unfolded the laptop to check if it made any difference. None. Not even a flicker.
• Driver updates - I tried to check for updates for the display driver and graphics card using HP Support and Nvidia apps, but I didn't find any updates. Everything seems up to date.
• External Display - This seems important. I also connected an external monitor now to see if the issue only happens on the internal display or also transfers over to the external display. I can't be 100% sure, but It never seems to happen when there's external monitor connected.  Moreover, once I connected the external monitor after the display got messed up. And the display corrected itself! Weird.

Please help if you have any idea about what might be causing this. Thanks!