How come every time i try and change my daily calorie goal it changes back and doesnt save?

Seems to be a bug currently. Look into the forums; there are more people reporting the same. Btw, none of them reports what system they use: app, and which os. Or computer and which browser. If they report the same to MFP support they won't be able to solve it.

Staff posted this:

We are aware of the problem with goals not saving for Android app users and have created an open bug ticket to investigate the issue further. Our team is actively working to identify the root cause and will aim to resolve it as quickly as possible. Please accept our sincerest apologies for any inconvenience this may have caused.

We will post updates on our Known Issues page as they are available. In the meantime, we've found a workaround. 

1. On the Dashboard (home page) of the app, tap the Edit near the upper right of the page
2. Tap on Edit Goal that should show on the large nutrient card near the top of the Dashboard
3. Make changes to your goals as needed and use the back arrow to return to the Dashboard
4. Tap Done Editing at the bottom of the screen
5. DO NOT visit the Goal settings via More (•••) in the bottom right. This will reset the goals again and you'll need to repeat the steps

From this thread: