Active USB port on shutdown

I have an Acer laptop. When I shut it down i.e switch off, the usb port I use for my mouse (I don't use the touchpad) sometimes stays active. By that I mean, the little light on the mouse stays illuminated evn when the computer is switched off and is not plugged in to a power source. This happens only sometimes. The fact that is happens on an irregular basis seems strange. I would have thoiught that the USB port was either on full time or off fulltime when the computer is switched off. Whereas this is not a real problem, it is rather strange that it happens intermittently. Anyone care to comment. Many thanks, Brian

i think most laptops have an active usb on shut down you can turn iit off in your makers setting

If you want BIOS you can set ErP Disabled to Enable, look for USB power delivery in soft off state (S5) and set it to Disabled.

Many thanks. Brian