After flashing LOS 17 in TWRP and rebooting only fastboot is appearing.
I did the following - what was wrong?
1. Coming from miui eu version (xiaomi.eu_multi_HMK20ProMI9TPro_V18.104.22.168.QFKCNXM_v11-10)
2. Format Data
3. Install lineage-17.0-20191124-UNOFFICIAL-raphael
4. Install open_gapps-arm64-10.0-micro-20191114-BETA
5. reboot-->fastboot screen
Thanks for your help!
I think vendor/firmware might be the problem. Actually I was told that coming from miui eu would solve this problem and I wouldn't need to flash vendor again.
So if I want to flash vendor/firmware again manually (as written in op): How do I know what version I need?
I'm happy to hear other solutions, too.