This isn't really surprising. LLMs are intended to be generally intelligent. They are spiky on the things frontier labs tend to benchmark against (software/math) but are not intended or expected to be great at everything. The general intelligence unlocks new workflows, it does not perfect existing ones.
That being said, I'm sure a frontier LLM could make some improvements to your CNN.
That being said, I'm sure a frontier LLM could make some improvements to your CNN.