[LG V30 Guides, News, & Discussion] mon0theist:
Magisk seems to have made major changes with the newest v22 release, and I discovered this morning after installing it that upon reboot, you get stuck in the Fastboot screen. Looks like the only way to fix is to re-flash Stock from LGUP and basically just start over. Fun!

I had no issues with Magisk versions up through 21.x, but unless you know something I don't know, don't attempt to upgrade to Magisk v22.

Maybe @ChazzMatt has more knowledge and can comment/elaborate on what the problem is

EDIT: I was able to just re-flash the TWRP-flashable 930b zip and Magisk 18 and it seems to be working, unfortunately I had already attempted factory reset so I might've been able to save myself a ton of time if I *hadn't* done that, now I gotta go through and setup my phone all over again, but I'm at least past the issue of being stuck in fastboot.

UPDATE

* Variant: US998 US Cellular/Carrier Unlocked

* ROM: Rooted Stock Pie (US99830b)

* Magisk: v21.4

So it seems the issue is not that it "soft bricks", but something about the new installation process of Magisk v22 goes wrong with the /boot partition, causing the phone to only be able to boot into Fastboot mode.

After getting my phone fully recovered and restored from the last failed attempt (and making a new TWRP backup), I attempted the v22 update again. First Magisk attempted to download and install the new v22 app, and then a popup notification said "additional setup is required for your device, press OK to reboot". So I hit okay, and that's when once again I got stuck in Fastboot with no other options.

If you have a TWRP/nandroid backup, you can easily fix this by performing the Master Reset process in order to boot into TWRP, and then just Restoring the /boot partition from your TWRP backup. This will get you back to Magisk v21.4 where you were before, which is where I'm currently at.

At this time, unless Magisk releases a TWRP-flashable .zip for v22, or unless there's a way to update to v22 via Fastboot, it doesn't look like updating to v22 will be possible, at least for the Stock Pie ROM.

I've seen on both reddit and XDA that several people are saying they updated to v22 without issue, but it's unclear if they were on Stock or Custom ROM. My guess would be that Custom ROMs are probably working fine and it's the Stock ROM that's having the issue.

Update 2

Someone suggested just renaming the magisk v22 apk to zip instead, and this seems to work.

What I did:

* Download the Magisk v22 apk from github

* Rename it to zip instead of apk

* Download the magisk v22 apk again, so now you have both a zip and an apk

* flash the v22 zip in TWRP

* Upon rebooting, I again got the "additional setup needed, press OK to reboot" prompt, so I did

* Successfully rebooted without getting stuck in fastboot, but upon opening magisk, I got the same prompt again

* manually installed the Magisk v22 apk from my file explorer

* opened the newly installed magisk app and again got the "additional setup" prompt, hit OK to reboot

* device rebooted again, and I think I got the prompt/reboot cycle one more time, but eventually after doing this, Magisk app opens and shows v22 with no more setup/reboot prompts

Seems to be working now as far as I can tell 👍