@Vhero Check Task Manager to see if there are any instances of LaunchBox or Big Box running in that case. If there's nothing wrong, then there's really no way that LaunchBox or Big Box could be killing CPU usage, unless there's some kind of insane Windows or .NET Framework bug. Also I'd recommend making sure your 100% up to date on all Windows updates. Are you running Windows 7 or Windows 10?
It also might be worth reinstalling the .NET Framework, as that has fixed some strange oddities for some other people as well. This kind of stuff is typically not related to the LaunchBox code, and is more likely due to some kind of corrupted install or corrupted driver (often the .NET Framework). Big Box often pushes systems to their limits, so it's no surprise that weird stuff will come out through Big Box.
@tjwoosta What version did you upgrade from? Were you on 7.16 before upgrading to 8.0? You can enable logging by changing the DebugLog line of the Settings.xml file, which may or may not help figure this out.