Writing to partition causes UFS error

[k-b-2]

I'm having a problem with writing to my Redmi Note 11 Pro+ 5G (mt6877). For some context, it went into a bootloop out of nowhere a few months ago and I'm trying to fix it or at least retrieve my data from it. I've done a backup of all partitions and the whole flash but obviously everything is encrypted, haven't yet unlocked bootloader because from my understanding it will wipe the data and the keys needed to decrypt it.

For now I'm trying to see if flashing boot with the stock ROM's boot will achieve anything, I used "python mtk.py w boot_a boot_a.img" but I get the following error after 1.6% :

DAXFlash - [LIB]: Error on sending parameter: UFS error (0xc0040060)
DAXFlash
DAXFlash - [LIB]: Error on writing pos 0x00200000`

I'm not sure if the UFS issue is related to the bootloader being locked or if it's Xiaomi-specific.
I also had the same issue when running "mtk.py da vbmeta 3". I noticed that get_current_slot() in mtk_da_handler.py is returning nothing - addresses 0x800 - 0x802 in misc contain 0s (0x804-0x809 have BCAB in utf-8 though, not sure if this is related to my specific model). That being said after hardcoding both vbmeta_a and vbmeta_b, I get the same error:

Progress: |██--------| 25.0% Write (0x1000/0x4000, ) 7.61 MB/sDAXFlash
DAXFlash - [LIB]: Error on sending parameter: UFS error (0xc0040060)
DAXFlash
DAXFlash - [LIB]: Error on writing pos 0x00200000
DaHandler
DaHandler - [LIB]: Error on patching vbmeta :(`

Any ideas about what the issue is or what I can do? Thanks.