Updating ui not working in fixed update .But it works in update

StoreCurency.text = PlayerPrefs.GetInt(GameStrings.curency, 0).ToString();

these lines of code is working fine in an update method. But when I put the same line in fixed update with nothing else is changed then its not updating . I would like to know why

Because FixedUpdate is part of the Physics Engine in Unity and not always in sync with the regular Update loop. You can try setting up a coroutine to be called from the FixedUpdate that after a WaitForEndOfFrame completes the UI update.