After the software update my mouse won't connect anymore

Maybe you can followe the instruction as below to reset K2 , it might be helpful

For all KeyMander 2 units regardless of firmware version, you can also perform a reset by pressing and holding Button 1 and Button 2 together for approximately 8 seconds.

which mouse model you used ?

Hi Blade,

What keyboard and mouse are you using and what console?

Are you using an external power supply?