sorry but I am a newbie and I apologize for my ignorance.
I read this forum and I tried to install the latest firmware (fw_dipper_miui_MI8Global_V184.108.40.206.QEAMIXM_5e74c6110e_10.0.zip) trough TWRP (I selected "Install" and simply tapped on the zip file and then swiped).
I then followed Lineage OS ufficial installation instructions: after "format data" and advanced wipe (cache and system) I installed Lineage 17.1 (adb sideloaded); then I wiped again Dalvik and Cache and rebooted.
Now I have the Lineage OS logo animation for 2-3 minutes and then the phone reboots to TWRP.
Anyone so kind to help? Did I installed the firmware the wrong way?
Edit: Ok, I solved installing the second last nightly of LOS 17.1!
There's an issue with latest LineageOS build, you may have read it on LOS thread.