Since I've exchanged my MOBO from MSI B85-G43 to Gigabyte sniper Z87, my mouse (Roccat Savu) started to behave strangely. Sometimes, upon turning on the PC, the mouse gets SUPER sensitive. It literally flies around the screen with the smallest touch. Also, the mouse's LED stops working. What works is unplugging the mouse, and plugging it back in. It happens in all 2.0 and 3.0 ports. It doesn't occur every time, but it only happens after I power down the PC (by turning the PDU off). Which I sadly do every night, so I have to unplug my mouse pretty much every day. It doesn't happen on reset.

I've updated the Savu driver to the latest release.

The mobo is second hand, and it might have been sold because of this flaw (the price was low), but I fail to see how the USB port itself can cause this. Seems more like a software issue to me? It happened both on previous & new installation of Windows 10, which I had to reinstall due to mobo change (activation).

Any ideas? I'd rather not RMA the mobo because of something that insignificant, but it's strange. All other periphrals work just fine on the same mobo, same USB ports. On the other hand, this problem began after I swapped the mobo...

I've looked for new USB drivers for this mobo on Gigabyte site, but haven't found any.