ByteDance Seed finds phase sensitivity behind DeepSeek long-context drift
Benchmark averages can mask periodic failure modes in long-context retrieval, so a model that looks solid on mean scores may still drop retrievals depending on where content sits in the compression window. Engineers running DeepSeek or similar KV-compressed models on RAG or agent pipelines should test retrieval across phase positions rather than relying on aggregate accuracy. The arXiv paper (2609.36322) offers the evaluation methodology to replicate.