Arturia/TuriBunny, I have the same thing happening on my win10 64-bit system. I get the midi control center process in the background process category of task manager, then after a good 3-5 minutes, the GUI comes up. I see this is an old case referring to WIn7. Should we open this up in a new thread/support ticket? It's very annoying. Took me several days to finally get to the point of being able to upgrade my matrixbrute!
FYI-MatrixBrute is directly connected to a usb port on the motherboard. Results are the same with the app whether any Arturia products are plugged in or not. Sounds like there must be some issue checking through a lot of USB devices (which I have).