Generative Fill creates random corrupted artifacts after 2–3 generations on MacBook Pro M1 (Photoshop 27.8, macOS 26.5.1)

I am experiencing a consistent issue with Generative Fill in Photoshop 27.8 on my MacBook Pro 13" with Apple M1 (16 GB RAM) running macOS 26.5.1. After launching Photoshop, Generative Fill works correctly for only two or three generations. After that, every new Generative Fill produces severely corrupted results with random black, red, yellow, or blue artifacts. Restarting Photoshop temporarily resolves the issue, but it returns after another few generations.

The problem occurs with both empty prompts and text prompts, and it does not depend on the size of the selection. It happens on multiple Canon CR2 RAW files that previously worked without any issues, and the corruption is visible not only in Photoshop but also in exported images. Interestingly, the Remove Tool, which also uses Generative AI, works normally and has never produced this problem.

I have already reset Photoshop preferences, reinstalled Photoshop, Camera Raw, and Adobe Bridge, and updated macOS to the latest available version. None of these steps resolved the issue. The behavior is fully reproducible on my system and only affects Generative Fill. I have attached several screenshots showing the corrupted output, in the hope that this will help reproduce and investigate the problem.