Match query is working differently for few inputs

Elastic Stack Elasticsearch
21

Hi Colin,
Am facing different problem like, if am entering text a/c b am getting only one record as response. But actually with that prefix two documents are there...

Example :
"A/C Bypass pulley"
"A/C Bypass pulley(Belts)"

My Query is:

GET pdlfull/pdlfull_type/_search
{
"query": {
"match_phrase_prefix": {
"description":"a/c b"

}

},
"sort":
{
"description.sort_field"
{
"order":"asc"
}
}
}
I have deleted the index and again gave the settings and mappings then indexed the data, only for this case( a/c b) am facing this problem..
Can you please guide me regarding this issue....