Can't recovery X20 Board

I’m attempting to recover X20 according to below link.
http://www.96boards.org/documentation/ConsumerEdition/MediaTekX20/Installation/BoardRecovery.md/

As below log, can’t download recovery.

dk.han@PE-SEVER:~/wrk/MTK/X20/mediatek-x20-aosp-16.10-image/Normal Image$ sudo fastboot flash gpt PGPT
target reported max download size of 134217728 bytes
sending 'gpt' (16 KB)...
OKAY [  0.136s]
writing 'gpt'...
OKAY [  0.023s]
finished. total time: 0.160s
dk.han@PE-SEVER:~/wrk/MTK/X20/mediatek-x20-aosp-16.10-image/Normal Image$ sudo fastboot flash preloader preloader_amt6797_64_open.bin
target reported max download size of 134217728 bytes
sending 'preloader' (170 KB)...
OKAY [  0.142s]
writing 'preloader'...
OKAY [  0.036s]
finished. total time: 0.178s
dk.han@PE-SEVER:~/wrk/MTK/X20/mediatek-x20-aosp-16.10-image/Normal Image$ sudo fastboot flash recovery recovery.img
target reported max download size of 134217728 bytes
sending 'recovery' (10338 KB)...
OKAY [  0.542s]
writing 'recovery'...
FAILED (remote: This partition doesn't exist)
finished. total time: 0.545s
dk.han@PE-SEVER:~/wrk/MTK/X20/mediatek-x20-aosp-16.10-image/Normal Image$

Somebody help me.

That’s very weird.

On my board I get an error on the GPT upload (which I ignored) and the rest of the recovery worked OK!

I dumped the GPT area and found something strange.

Compared with the PGPT file, Bit[3] of each byte was stored as 0.
I suspect that there is a bug when updating GPT in lk.