Premiere Pro playback and export glitch / pixelation issue

Hi, I have a serious playback issue in Adobe Premiere Pro.
The video in the Program Monitor becomes pixelated, blocky and glitchy during playback. However, the original video files play normally outside Premiere Pro.

This issue also affects exports — the exported video sometimes contains the same pixelation/glitch artifacts.

I already tried: clearing media cache, GPU acceleration on/off, updating drivers, changing renderer settings, lowering playback resolution, reinstalling Premiere Pro, and resetting preferences.

My PC specs: Ryzen 5 7500F, A620 motherboard, 16GB DDR5 RAM, RTX 5060 GPU.

I attached a screenshot. Any help would be appreciated.
This issue only happens inside Premiere Pro.