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