Yeah, you should downgrade your sysnand first. Search google for "[MEGA] [CIA/BIN]
MSET 4.X & 6.X backups, Browser backups, Update packs (All Regions)" and create an account
on the ISO site I can't name on GBATemp and download the proper 9.2 update pack for your 3DS. Pay attention to Region and O3DS/N3DS, because if you get the wrong pack you WILL brick.
You'll need to use one of these two versions of sysupdater:
julian20:
https://gbatemp.net/threads/407888/page-95#post-5923820
safesysupdater:
https://gbatemp.net/threads/wip-safesysupdater.409392/
The second one is probably safer. Copy the /updates/ folder from your update pack to SD:/, run sysupdater through menuhax HBL, then press Y to downgrade when you see non-glitched text (any crash or glitching you see when running the program, reboot: it might require several reboots)
When it's done let it reboot and hope you're on 9.2. If it crashes, take out your SD card and wait about a minute, then report back if it crashed again.