Boolean MUST Match in "Nested" type Not working for timestamp - precisely

[baig (Baig Awan)]

Hi, couldn't find a matching topic to continue so opening a new issue.
I am currently using ES version 7.6.2.
I have a list of similar json objects where one of each objects also contains a field timestamp. When I do a search query based on timestamp it works until the decimal but doesn't differentiate once timestamp has decimals. For example, if I am trying to match timestamp:1590754048418.2524, it will return all the matches where timestamp:1590754048418.xxxx.

To reproduce:

PUT my-index-000001
{
  "mappings": {
    "properties": {
      "USER_LOGS": {
        "type": "nested" 
      }
    }
  }
}

PUT my-index-000001/_doc/1
{
  "group" : "fans",
  "USER_LOGS":[
      {
         "severity":"INFO",
         "message":"user message1",
         "msg_timestamp":1590754048414.2043
      },
      {
         "severity":"INFO",
         "message":"user message2",
         "msg_timestamp":1590754048418.2524
      }
    ]
}

GET my-index-000001/_search
{
  "query": {
    "nested": {
      "path": "USER_LOGS",
      "query": {
        "bool": {
          "must": [
            { "match": { "USER_LOGS.severity": "INFO" }},
            { "match": { "USER_LOGS.message": "user message2" }},
            { "match": { "USER_LOGS.msg_timestamp":  1590754048414.2043 }}
          ]
        }
      }
    }
  }
}

In the GET my-index-000001/_search I am expecting an empty search but it still returns the doc/_1. I have started to think that ES just does not process the timestamps after decimals, is that an expected behavior or am I missing?
I want to pull the correct log messages stored at different times.

Thanks!