Pi3 as Server - Win7 64bit Client ok vs. Win10 64bit Client nok

I use a Pi3 as Server connected to a USB-RS232 converter and to another USB device (PLC).

The Client under Win7 64bit is working perfect - installing 2 drivers at first connect (usb hub + usb controller) + installing the device (internal a usb to serial converter).

The Client under Win10 64bit is also working for the USB-RS232 converter, but not for the PLC.
On first install, there was only one driver installed (VirtualHere USB 3 eXtensible Host Controller) instead of the two in Win 7. The device itself is only recognized as USB Composite Device with a yellow triangle.

I tried already vhusb64 -y -> Restart -> same behavior.

Are there any ideas, how to solve this?