Hello, everytime I attach an USB Keyboard I get three to four times the same popups opened immediately:
[Dom0] Operation execution: Do you want to allow the following operation? [...] Source: sys-usb Operation: qubes.InputKeyboard Target: dom0
I think this is not a normal behavior as the popup should appear only once? What is the reason and how can this be fixed?
Maybe your keyboard is a composite USB device that consists of four USB HID Keyboard devices?
Separate USB HID device for main keyboard, separate USB HID device for multimedia keys etc.
I have also experienced a keyboard being displayed 5 times due to a small loose contact. It could therefore also be due to the condition of the USB plug or socket. When you confirm the keyboard, does an error occur or is it accepted without any problems?
I don’t know if it is displayed there but you can try to enter lsusb in the respective appvm or dom0 to list the USB devices, maybe the keyboard appears there several times what confirms the theory of @apparatus. Many keyboards are now like this, especially gaming keyboards.
Experienced this too, like many others. I think we can all agree it’s something like:
So make sure you’re allowing them whatever they need 
Thanks for your answers that clarified everything. I do not face any errors when confirming.