c# - Multiple requests with Include and Where condtition throws exception -

i using asp.net core ef core. if multiple requests same controller method of thoes requests throws: object reference not set instance of object, without detailed explanation. if 1 request controller- no exception occur.

here reconstructed example of existing system

    public class player {     public int id { get; set; }     public string name { get; set; }     public team team { get; set; } }  public class team {     public int id { get; set; }     public string name { get; set; }     public list<player> players { get; set; }  } 

this code throws exception

    public async task<list<player>> test()     {         using (repository.dataprovider.repodbcontext db = new repository.dataprovider.repodbcontext())         {            return await  db.players.include(x => x.team).where(x => x.team.id == 1).tolistasync();         }     } 

i did little research , realize exceptions occurs if there combination include , where statement using same property (team in case). if remove include or where works fine.

is sort of bug or doing wrong?

data player table:

edit: reproduce problem https://github.com/brivvirs/efcorebug