Laptop consumes about 2% battery capacity per hour in standby mode

It's not a bug, it's a feature

High-performance laptops tend to consume more energy in standby than other devices. This especially affects the XMG FUSION and XMG NEO series with opto-mechanical keyboards. Reason: the keyboard also consumes a bit more than 1W in standby because the keyboard keeps the opto-mechanical switches alive. There is a small infrared light barrier under each individual key, which is supposed to register the keystroke.

Keyboard wakes system from standby

The keyboard is powered because it is supposed to be able to wake up the system from standby. This results in a total power consumption (with power supply, measured at the socket, including power loss of the power supply) of up to 1.8 watts in standby with an otherwise fully charged battery. This system feature is hardwired into hardware and cannot be disabled. A complete shutdown of the keyboard only takes place in hibernate (S4, Suspend to Disk) or when powering down (S5).

Hibernate instead of Standby

We generally recommend using the hibernate mode. Practically, once the system is in hibernate, it does not consume any energy anymore - the laptop shuts down completely. Before that, the system memory's content is frozen and cached on the SSD. The system proceeds quite intelligently: it does not write the entire RAM capacity to disk, but only the actually used parts of it. Thus, before switching to hibernation, it is worth closing some windows and programs that you probably won't need anymore.

By default, the standby mode automatically switches to hibernate after 180 minutes. You can shorten this period in Windows' advanced power options (see screenshot). You would have to do this for each of the available power profiles (Energy Saver, Balanced, High Performance), if available. For hibernation to be available for selection in the Start menu, you will have to activate it first (see screenshot).

Related article: How to remove Standby from the user experience (optionally: replace with Hibernate)