I had this issue after using Nuendo for just 1 week. The solution for me was to uninstall the old driver (from the Windows Settings - Apps program) and then re-install the same driver. It is very quick and I was not required to unplug all the USB stuff as the installation manual instructs. But your mileage may vary. For quick reference, here’s the page with the driver info: Yamaha Steinberg USB Driver Updates and Downloads | Steinberg
As to why this happened…
For me, Nuendo is installed on a church computer that is used once a week when we record our praise band (with social distancing of course). So, this Nuendo had not been used in a week and only a few hours of one day in the last week was it used at all. However, there was a Windows Update in the last week…which leads me to conclude that the Windows Update overrode the Steinberg driver somehow. To back this theory, before I reinstalled the driver, I was snooping around the device manager looking for the Yamaha Steinberg driver. It should be under the “Sound, video, and game controlers” section of the device manager. While I did find an entry for “Yamaha TF”, when I right-clicked on properties, it said the Manufacturer was Microsoft. After re-install, the properties now show it to be “Manufacturer: Yamaha Corporation” and it’s working now.