I appreciate that this thread is now a couple of years old but I’ve just had and resolved the same / similar problem. In my case it was standalone Groove Agent SE5 on Windows 11 unable to open the Yamaha Steinberg USB ASIO driver for my Steinberg UR22C (although it was there when running Groove Agent through Cubase). Turned out to be a simple resource locking conflict… I had opened Cubase earlier which had presumably locked onto the driver. Although I had since closed Cubase, it was still running in task manager. Once I forced Cubase to end in task manager, the driver freed up and I was able to assign it in standalone Groove Agent. Result! The moral of the story… check whether you have any other apps open that may be holding on to exclusive control of the ASIO driver. Hope this helps if you find it.
Have you tried the ASIO4ALL driver?