Health App not possible to add new data and no Favorites in the Dashboard
I have an iPhone 5s with iOS 10.2.1 and I have always used the Health App to track key indicators.
Some of them with a manual input (weight, body fat percentage), some automatically (steps) and some through linked apps (e.g. calories from MyFitnessPal or sleep time from Sleep Cycle).
It has always worked fine until a couple of days ago when I found out that the sleep time was not stored and also that I couldn't add manually the new values for Weight and Body Fat Percentage.
Also, I found some issues with the Favorites feature: I had previously set up to have in the dashboard the Weight and the Body Fat Percentage, but they are not there anymore.
When I activate for any indicator the "Add to Favorites", it goes to the Dashboard, but when I exit the Health App and get in it again, the Dashboard is empty and the "Add to Favorites" toggle in the Indicator is lost.
I already read multiple discussions and tried many solutions (turn the iPhone off and on, "hard reset" (pressing Home and Start button together until Apple logo appears) and few minor ones), but with no results.
iPhone 5s, iOS 10.2.1