Index configuration does not support sparse values

Getting the error “Index configuration does not support sparse values”, “details” :

My index similarity is set to dotproduct afaik this metric is supported. I am generating sparse vectors via splade. Screenshot of example of data below as well as the query which produces the error.

Update: I have also tried with the BM25 encoder and also did explicit weighting via hybrid_score_norm but it is still not working

IndexDescription(name='fedspeechdot', metric='dotproduct', replicas=1, dimension=768.0, shards=1, pods=1, pod_type='p2.x1', status={'ready': True, 'state': 'Ready'}, metadata_config=None, source_collection='')