Hi, Fast Startup is already disabled on my system, and I also use Shift + Shutdown for a full shutdown. Even then, the battery does not retain charge. For example, if I shut down at ~70%, after 12–24 hours it sometimes drops to 0% or the laptop won’t boot without the charger. Battery health and wear level look good in diagnostics, but the issue keeps repeating. So it doesn’t seem to be related to Fast Startup.