AutoGGUFEmbeddings with nomic-embed-text-v1.5.Q8_0.gguf not able to achieve high context length

[pwyang123]

nomic-embed-text-v1.5.Q8_0.gguf claims to reach 8192 context length, but AutoGGUFEmbeddings loaded with this model still have only 512 context length even model was setNCtx(8191) and model attribute nCtx has 8191 as value. any advice on how to config model to be able to increase context length would be appreciated, thanks.
pipeline snippet:

document_assembler = DocumentAssembler() \
    .setInputCol("text") \
    .setOutputCol("document")
autoGGUFModel = (
    AutoGGUFEmbeddings.loadSavedModel("path_to/nomic-embed-text-v1.5.Q8_0.gguf", spark)\
    .setInputCols(["document"]) \
    .setOutputCol("embeddings") \
    .setBatchSize(4) \
    .setNGpuLayers(99) \
    .setNCtx(8191)\
)
pipeline = Pipeline().setStages([document_assembler, autoGGUFModel])

[maziyarpanahi]

Hi @pwyang123
How do you know the context length is 512 and not more?