Don’t follow the original guide
➜ ~ cd Downloads ➜ Downloads fastboot flash vendor_boot vendor_boot.img Sending 'vendor_boot_a' (65536 KB) OKAY [ 0.516s] Writing 'vendor_boot_a' OKAY [ 0.244s] Finished. Total time: 0.761s ➜ Downloads fastboot flash dtbo dtbo.img Sending 'dtbo_a' (16384 KB) OKAY [ 0.115s] Writing 'dtbo_a' OKAY [ 0.066s] Finished. Total time: 0.181s ➜ Downloads fastboot flash boot boot.img Sending 'boot_a' (65536 KB) OKAY [ 0.508s] Writing 'boot_a' OKAY [ 0.228s] Finished. Total time: 0.737s ➜ Downloads fastboot reboot recovery Rebooting into recovery OKAY [ 0.000s] Finished. Total time: 0.051s
You need to boot dtbo and boot too.
Thanks to: https://www.reddit.com/r/LineageOS/comments/11y3aur/comment/jdafm2k/?utm_source=share&utm_medium=web2x&context=3