Creating the stick: Disk manager may interfere. Open a virtual console, insert the stick and run ‘woeusb -d Win10_2004_German_x64.iso /dev/sdX --tgt-fs ntfs’ from there.
Windows install: Setup gets confused with more than one disk. Unplug all but the one where Windows goes.
Setup creates all of Microsoft reserved partition, EFI system partition and Basic data partition. It claims it successfully performed all 5 steps of installation. Finally it says it could not restart the computer and recommends to install again (with the same result). Removing the other disks terminates the loop.
Lots of hand-holding required . Eventually 3 machines got it. The most daunting install was a drive with two chunks of free space:
3400G:~ # fdisk -l /dev/sdc
Disk /dev/sdc: 1.84 TiB, 2000398934016 bytes, 3907029168 sectors
Disk model: ST2000DM001-1CH1
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: gpt
Disk identifier: 609FED7F-FC4F-43A7-9D25-44783253D69C
Device Start End Sectors Size Type
/dev/sdc1 2048 34815 32768 16M Microsoft reserved
/dev/sdc2 33761280 3770382335 3736621056 1.8T Linux filesystem
/dev/sdc3 3770382336 3770587135 204800 100M EFI System
/dev/sdc4 3770587136 3905975094 135387959 64.6G Microsoft basic data
/dev/sdc5 3905976320 3907026943 1050624 513M Windows recovery environment
3400G:~ #
You definitely learn things you never wanted to know. If you want to get things done only stay during the install with one drive and one chunk of free space preferably at the end of the drive.