Sqlite database is not working(no update/insert) properly

To make single thread connection i converted my SQLHelper class to Singleton and i used AppContext got from Application class is used to create database object. but after that no add and update method able to save data in database. on call of db.insert method it returns 1. also data shown in list but when app is reopen everything is lost. Here reopen means closeg app from cache and restart it

testing Device : MOTO G first generation