Is this a glitch/bug with the new Ubuntu 26.04 Resolute Racoon?

For context, I am a Linux newbie who never went deep tinkering with different things in Linux, just basic optimisations like SSD Trimming, Zram, auto-cpufreq etc. I recently upgraded to the Ubuntu 26.06 version and I have been getting this problem where every few minutes, my display randomly goes a bit dim for no reason. This is despite the slider being maxed out. This never happened on Windows or Ubuntu 24.04 which I used before.

Some more details: CPU & GPU: Ryzen 5 8640HS, Radeon 760m; (Zen 4 and RDNA 3) Display type: IPS 60Hz Status while observation: Plugged in All drivers updated, all software updated, no unnecessary tweak made

Is this a driver glitch or a problem with Ubuntu itself?