Inaccessible boot device on external win installation on mac 2019

i have a MBP 2019 (Sonoma) and an external ADATA se920 1TB. I tried, after I read several answers on the web, to install win 10 and win 11 on the external drive (dual boot). I tried with Virual Box, tried with Macrium after installing with Bootcamp, but I come to the same problem: inaccessible_boot_device. I have lowered the boot security options. Still the same. When I start MBP with option key pressed, I get mac os, windows (bootcamp) and EFI boot. When I choose the EFI boot, I get the problem. When I try the start up utility on mac, I do not see the external windows installation (only sonoma and bootcamp). Can anyone help?