If you are experience troubles with partial progress loss after closing your game and finding it didn't save,  please know there is a Save Button feature in HPHM that can greatly assist users who experience partial progress loss from time to time after closing out the app.
To access the Save Button:

1. Tap your profile icon in the top left corner of the screen.

2. Tap the gear symbol for Account Settings

3. Tap the button that says "Save Game"