USB-C Power Delivery Battery Health works wrong way

My Notebook: Asus Rog G14 GA401-IU.

I set the battery health mode to: asusctl -c 60

I have a USB-C docking station with Power Delivery. If I don't have the main power adapter plugged in, but only the USB-C power delivery via the dock, the battery charging state goes:

• battery is discharged from 60% to 57%
• then battery is charged to 60%
• and the same repeated

So the charge/discharge frequency is very high, I think this is very bad for the battery and maybe also other components.

If I plug in the main power supply, it is correct:

• battery is NOT charged until self-discharged under 58%
• then battery is charged to 60%

Is this a software or hardware/firmware bug?