Gemma 4 tanks in early hallucination tests

Google’s pivot to "Thinking Mode" reasoning seems to have come at the expense of retrieval-augmented precision.

• –The flagship 31B Dense and 26B MoE models are excelling in synthetic reasoning benchmarks but failing practical grounding tests in RAG pipelines.
• –Users report that the E4B and E2B edge variants are particularly prone to "nonsense" responses when RAG context is missing, suggesting a lack of robust refusal mechanisms.
• –The 26B A4B variant’s MoE routing may be sacrificing factual fidelity for its 4B-class inference speed, a trade-off that is proving controversial for production deployment.
• –This feedback mirrors a broader industry trend where increased "reasoning" parameters sometimes lead to more convincing but equally incorrect hallucinations.
• –Comparison benchmarks show Gemma 4 trailing behind competitors like Grok 4.20 in reliability, a significant blow to its "intelligence-first" branding.