[OnePlus 9] shadabkiani:
It didn't as I already mentioned in my post.

I flashed every single partition; except for userdata. For the record, I unlocked bootloader (fastboot flashing unlock) as well as critical flashing (fastboot flashing unlock_critical). I took the following steps:

From the bootloader mode:

fastboot -w

fastboot flash super super ### This is the one confusing me. Is this the right way to flash this?

fastboot flash keystore keystore

fastboot flash carrier carrier

fastboot flash opluslog opluslog

fastboot flash rawdump rawdump

fastboot flash ALIGN_TO_128K_1 ALIGN_TO_128K_1

fastboot flash ocdt ocdt

fastboot flash dinfo dinfo

fastboot flash oplusreserve2 oplusreserve2

fastboot flash oplusreserve3 oplusreserve3

fastboot flash oplusreserve4 oplusreserve4

fastboot flash oplusreserve5 oplusreserve5

fastboot flash DRIVER DRIVER

fastboot flash qmcs qmcs

fastboot flash dip dip

fastboot flash dip dip

fastboot flash limits limits

fastboot flash limits-cdsp limits-cdsp

fastboot flash logdump logdump

fastboot flash uefivarstore uefivarstore

fastboot flash vm-data vm-data

fastboot flash mdcompress mdcompress

fastboot flash connsec connsec

fastboot flash rtice rtice

fastboot flash kernel_log kernel_log

fastboot flash android_log android_log

fastboot flash qsee_log qsee_log

fastboot flash ALIGN_TO_128K_2 ALIGN_TO_128K_2

fastboot flash oplusreserve1 oplusreserve1

From the fastbootd mode (these are critical partitions; can't be flashed from bootloader):

fastboot flash xbl_a xbl_a

fastboot flash xbl_config_a xbl_config_a

fastboot flash xbl_b xbl_b

fastboot flash xbl_config_b xbl_config_b

fastboot flash aop_a aop_a

fastboot flash tz_a tz_a

fastboot flash hyp_a hyp_a

fastboot flash bluetooth_a bluetooth_a

fastboot flash abl_a abl_a

fastboot flash dsp_a dsp_a

fastboot flash keymaster_a keymaster_a

fastboot flash devcfg_a devcfg_a

fastboot flash qupfw_a qupfw_a

fastboot flash uefisecapp_a uefisecapp_a

fastboot flash imagefv_a imagefv_a

fastboot flash multiimgoem_a multiimgoem_a

fastboot flash featenabler_a featenabler_a

fastboot flash aop_b aop_b

fastboot flash tz_b tz_b

fastboot flash hyp_b hyp_b

fastboot flash bluetooth_b bluetooth_b

fastboot flash abl_b abl_b

fastboot flash dsp_b dsp_b

fastboot flash keymaster_b keymaster_b

fastboot flash devcfg_b devcfg_b

fastboot flash qupfw_b qupfw_b

fastboot flash uefisecapp_b uefisecapp_b

fastboot flash imagefv_b imagefv_b

fastboot flash multiimgoem_b multiimgoem_b

fastboot flash featenabler_b featenabler_b

# The following are even more critical. They are generally not flashed even by firmware. But I still flashed them as well.

fastboot flash param param

fastboot flash persist persist

fastboot flash frp frp

fastboot flash persist_bkp persist_bkp

fastboot flash cdt cdt

fastboot flash ddr ddr

fastboot flash mdtpsecapp_a mdtpsecapp_a

fastboot flash mdtp_a mdtp_a

fastboot flash mdtpsecapp_b mdtpsecapp_b

fastboot flash mdtp_b mdtp_b

fastboot flash devinfo devinfo

fastboot flash apdp apdp

fastboot flash logfs logfs

fastboot flash modemdump modemdump

fastboot flash storsec storsec

fastboot flash secdata secdata

fastboot flash tzsc tzsc

fastboot flash spunvm spunvm

fastboot flash apdp_full apdp_full

fastboot flash abl_log abl_log

fastboot flash hyp_log hyp_log

fastboot flash modemst1 modemst1

fastboot flash modemst2 modemst2

fastboot flash fsg fsg

fastboot flash fsc fsc

Note:

1. When making backups, I did not name the dumps as *.img. Nevertheless, the backups are the same. As I tested by backing some partitions with .img in the name, and without them as well. The hex editor did not show any difference.

2. I used the fastbootd mode of LineageOS boot.img. The stock boot.img was not taking me to fastbootd mode.

I have attached the file list of my backup dumps.