Intel Iris Xe glitches and flickering

[Hs_Oft]

I faced a strange graphics bug on my Dell Vostro 3500 with Windows 10, i5-1135G7 processor and built-in Intel Iris Xe Graphics.

I got and activated it on 17 Sep 2021, then 10 days later did some upgrade (installed SSD, increased RAM, re-installed Windows and all OEM drivers), and it worked fine. About 1st or 2nd of October there appeared glitches such as color strips, black squares, screen twitching and flickering. It's strange that they appear only in certain Windows apps and web pages. Mostly often they are seen in the PIN code screen, Firefox and Intel Graphics Command Center. They never appear in BIOS menu.

I suspected software issues, so I re-installed Windows again and tried the latest driver from Dell (27.20.100.9635) and from Intel website (30.0.100.9864), though the latter installed with errors and detected the GPU as Intel UHD graphics. The bug persisted regardless of driver version.

How I reproduce it:

- open Firefox, go to yandex.ru and search "физический движок на GPU" (physics engine on GPU). The screen starts blinking and turns off.

- a screenshot of that page, or even a part of it with search query, does the same 😲