Nitro 5 screen sometimes flicker at the top

My nitro 5 sometimes does this randomly and most of the time it doesn't, when it does i can switch to 60hz and the problem will go away , i tried everything to reproduce the problem but to no avail.

I saw another topic with the same problem but there was no answer, and besides mine only flicker for a while, not permanently.

Please help me troubleshoot the problem, i cant afford to buy another one or get anything replaced because its out of warranty 🥲 thank you

P/s: idk if its gonna be of any help but, till now the flickering only happen at night, and is out of nowhere, maybe i didnt have time to test it out during daytime but, just in case. And its def not related to heat cause ive been playing heavy games for 5-8 hours on it for a few days without encountering the issue