Win10 on usb set up hanging

[win10try]

Hi all, brand new here. Got a problem that might be related to WinToUsb and hope to get some help.

Today I successfully installed a win10-1803.iso on an external/usb drive using WinToUsb (latest version).
I can boot the drive and Windows 10 starts, logo appears, then the spinning dots appear and the logo disappears, and then...... the dots just keep spinning for hours and set up does not continue.

What could be the cause?

(BTW: It's a 1TB drive, which I had to split into 2 smaller drives bc WinToUsb would not proceed in the installation set up.)

[admin]

Please check to see if the USB drive is connected to your computer via a USB 3.0 port?

[win10try]

Please check to see if the USB drive is connected to your computer via a USB 3.0 port?

It is!Chipset, cable and drive are USB 3.0

I think WinToUsb did everything it is supposed to do. Windows 10 is properly installed on the external drive.
Windows 10 starts, but after showing the logo, the spinning dots start spinning and spinning and spinning....

Must be a Win10 thing, but I hoped that you guys have some experience with this problem, and thus a solution.

[admin]

The issue about long wait times during installation is usually due to the fact that the USB drive is not suitable for creating portable Windows. For an operating system boot drive, 4K random read/write speed is very important. If the 4K read/write speed of a USB drive is too slow, then the USB drive is not suitable for creating portable Windows. Please use CrystalDiskMark to test the 4K random read/write speed of both USB drives.

How to Run a Hard Drive Speed Test:
http://www.buildcomputers.net/hard-drive-benchmark.html

[win10try]

The issue about long wait times during installation is usually due to the fact that the USB drive is not suitable for creating portable Windows. For an operating system boot drive, 4K random read/write speed is very important. If the 4K read/write speed of a USB drive is too slow, then the USB drive is not suitable for creating portable Windows. Please use CrystalDiskMark to test the 4K random read/write speed of both USB drives.

How to Run a Hard Drive Speed Test:
http://www.buildcomputers.net/hard-drive-benchmark.html

Thanks for your answer and taking the time for it on this festive day, LH. Happy 2019 !

However, I don't understand your answer. There is/was no issue with long waiting times during installation. The WinToUsb-installation went fast and well.
The issue is (probably) with Windows10 itself, searching for something like a driver maybe? Like I said: Windows10 does start successfully when booting from the drive.
What (does not) happen next is the problem.

Cheers

[admin]

If you have another USB device, try to see if other USB devices can start Windows successfully.