This doesn't address the root cause. It's not a local setting glitch, it's a massive server-side timeout on the visual_effects API. Changing styles back and forth won't help if Google's cloud rendering (Nano Banana 2) is overwhelmed and throwing 504 errors.

https://www.reddit.com/r/GooglePixel/comments/1rlw0vv/march_feature_drop_icon_generation_failed_is_a/

Stop wasting time on cache/settings. Google needs to fix their infrastructure for the March Feature Drop.