[FTS] : Inconsistencies in score explanation in vector search

Steps to repro

1. Created a 4 node cluster with 2 fts node, 1 kv and 1 query
2. Created a couchstore bucket and loaded some docs
3. Created a search index with with 2 mapping child fields
   1. field - content, type - text, searchable as - content, analyser - en
   2. field - vector, type - vector, searchable as - vector, dimension - 384, similarity metric - dot_product
4. Ran a search query on the index with "explain": true
5. The search query returns inconsistent scoring explanation

The first 3 docs returned have consistent results and correct score explanations

The remaining docs have all inconsistent results{}

First 3 docs

1st result doc 17 correct explanation

2nd result doc 24 correct explanation

3rd result doc 21 correct explanation{}

The remaining docs have all incorrect score explanations and inconsistent results