I'm having similar problems but have noticed something not yet commented upon.
The Problem
I set the management system by default to Best battery health as I normally keep it plugged in. However, when it is not plugged in, and the battery falls to a certain level it automatically changes to Optimize for battery runtime.
Example:
1. As I write this my charge level is at 17%.
2. While plugged in and charging I set it to Best Battery Health.
3. I turn off the charger and I visually see the Energy Management scheme automatically changing to Optimize for Battery Runtime. (However this is only because I am looking at it; it normally happens without any visible warning that a change has occurred)
4. I try to change it back to Best Battery Health while unplugged but it will not accept my changes.
5. I turn the charger back on... but the Energy management scheme has not remembered my preferences and remains on Optimize for battery runtime, so I have to manually change it back. I can only change it back when it is plugged in.
Conclusion
It appears that the Energy management scheme will automatically change to preserve Battery Runtime if batteries are low, but will not remember the users preferences. If the power is cut off even for a second and the batteries are low to start with then the setting will change without users being aware.
Proposed solutions
1. Enable a popup that explains the settings have changed to alert users.
2. I am happy that it automatically changes to Optimizing for Runtime when my batteries are low, however I want it to automatically revert to Best Battery Health when I plug it in again. Can we have default settings that work both ways.
3. In the help section explain that the setting will change when the battery falls to x?%, and then also that the setting will (hopefully) change back when the unit is plugged in. This will hopefully stop confusion.
Thanks, hope this contributes to solving the problem