You have to mod a 4cores TWRP version or use the one I provided on my leech server .I was on lineage-16.0-20190620-UNOFFICIAL-h815 when I got a bootloop. I tried a number of time to enter in TWRP (twrp-3.3.1-PREVIEW-191_g4_P installed) through the recovery (i.e. answering yes to both questions about factory reset). Thanfully I can still enter in fastboot and download modes.
Unfortunately I am on a Macosx and although I have FWUL in a virtual box, I cannot see the device in the VM for some reason, and it is not a good idea to flash through a virtual machine. So, I have tried to flash a boot and twrp through fastboot, but I am still in a bootloop and cannot access TWRP:
So, what I am doing wrong? Any hints? Thanks!
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