So if you do not touch it overnight, it loses 0% battery? Because in off mode it will take months to lose even 1% of the battery. I had my switch on the shelf untouched for 6+ months, and after powering it on after more than half a year after putting it in the case it had 98% battery.
You probably think its off, but its actually in RCM mode. The only way to check is to plug a light into the USB-C slot and see if it lights up, or letting it sit for a day and seeing if you lost any battery. No other way to know.
To be clear, its a different RCM mode than when you power it on. Injection wont work but the switch is still on. Its more like a Zombie mode.