I've directly faced this problem with automatic code formatters, but it was back around Claude 3.5 and 3.7. It would consistently write nonconforming code - regardless of having context demanding proper formatting. This caused both extra turns/invocations with the LLM and would cause context issues - both filling the context with multiple variants of the file and also having a confounding/polluting/poisoning effect due to having these multiple variations.

I haven't had this problem in a while, but I expect current LLMs would probably handle those formatting instructions more closely than the 3.5 era.