Hi, thank you for your reply,
I have tried different USB3 slots (only one the cable with the keyboard icon plugged in).
I updated my windows
I updated my ChipsetDrivers + USB3 drivers
I updated my BIOS (latest version is in 2013 though)
Also, when i login the keyboard will react normally for about 1 to 3 seconds when the slow key detection problem starts.
When the problem starts, I can hear windows make a sound that a device is connected/disconnected. After arround 30 seconds windows makes the same sound again. A few seconds after the 2nd time windows makes this sound, the keyboard works normally again. It seems like windows uses different drivers when logging in, disabling them after login and taking a lot of time enabling the correct drivers for my keyboard?
UPDATE:
After a few reboots, windows stop making the connected/disconnected sounds. The problem with my keyboard is still there, it seems the drivers load a little bit faster now though.
Before posting my first post I deleted all HID keyboard Device entries in the Device Manage to ensure no drivers from my previous keyboard exists.
When I look at the Device Manager again I can see 6 entries for "HID keyboard device" which sounds weird to me since only 1 keyboard is connected.
UPDATE 2:
Updated BIOS