I've tried to search for this movie directly via our API (title "Blue", year=2018) and it is in fact returned correctly as 11th match of 92. So AFAIK the problem isn't on our end:

https://api.themoviedb.org/3/search/movie?api_key=###&language=en-US&query=Blue&page=1&include_adult=false&year=2018

returns:

{  
  "page": 1,  
  "total_results": 92,  
  "total_pages": 5,  
  "results": [  
  ...   
 {  
      "popularity": 0.6,  
      "id": 641401,  
      "video": false,  
      "vote_count": 0,  
      "vote_average": 0,  
      "title": "Blue",  
      "release_date": "2018-08-24",  
      "original_language": "en",  
      "original_title": "Blue",  
      "genre_ids": [],  
      "backdrop_path": "/jXuq37dUpBINhko6FKeJpA3waBL.jpg",  
      "adult": false,  
      "overview": "Based on true events- A young woman struggles to piece her world together after a botched suicide attempt.",  
      "poster_path": "/lHKkEMcpDHosDOC0TsozBoyXRSF.jpg"  
    },  
   ...  
  ]  
}    

You can achieve the same result when you search for this title using our web search:

https://www.themoviedb.org/search?query=blue%20y%3A2018

Also, there's some improvements I'd like to find time for around matching exact titles better. It's a known issue.