data is not coming from DB even there is data in the table, ORM is Dapper

I am facing a strange issue, i am not sure what happened to code, it was working perfectly yesterday. I have data in table and am using below function to retrieve it from DB. i am using My SQL. when the application is started the data fetch correctly, but once we hit few times to DB for some tractions like save/update/delete. it stops to fetch records from DB or you can say it stops communicate with DB, but it the connection is building. i have verified that.

Below is my code:

 public List<AcademyTeamsEntity> GetAcademyTeams(int academyId)
    {
        using (IDbConnection db = new MySql.Data.MySqlClient.MySqlConnection(ClsConnectionString.connectionString))
        {
            string query = @"SELECT * FROM academyteams where AcademyId=" + academyId + " order by CategoryId asc ";

            return db.Query<AcademyTeamsEntity>(query, commandType: System.Data.CommandType.Text).ToList();
        }
    }

Please suggest what is the mistake i am making. thanks in advance.