[ASUS ZenFone 6 (2019) Questions & Answers] bobs50000:
Alright. I know it's been a while since my other post, but I wanted to leave my latest here for any body else reading.

I could not get LineageOS 16 to work at all. The best I was able to get was LineageOS 16 booting, getting to the first time setup saying "Just a sec...", and then a black screen. Holding the power button or using the volume buttons caused the side controls to show up, like the "Power off", "Reboot", or the volume slider to appear, but the rest of the screen was black. After about a minute or two. It would actually freeze up, and restart. But that was it. I mentioned it in my other post, but the recovery for LineageOS 16 takes 5 minutes to boot, I timed it. Its unusual, something must be wrong.

So my options were LineageOS 17 (Android 10) with a horrible camera, or Stock ZenUI (also Android 10).

So I'm choosing Stock, so that I can have a decent camera experience. I really wish I could have LineageOS on this phone, and is one of the major reasons I bought this phone, but the camera app on LOS 17 breaks it for me. I'm just going to have to put up with Stock shenanigans and limitations.

Because I have been flashing so many different times, the state of my device is quite messy. I've been following these steps I wrote down to get a good install every time:

Boot into the bootloader

Use flashall.cmd to revert Slot A back to Android 9 ZenUI v1906.167

Without entering the system, boot into recovery

I edited the end of flashall.cmd so that it wouldn't automatically reboot to system

Apply the ZenUI v1909.194 update, which will end up in slot B

While still in the recovery, use the "Wipe data/factory reset" option

Boot into the bootloader, then back into recovery, to end up in slot B

Reapply the ZenUI v1909.194 update, which will now end up in Slot A. Both slots now have ZenUI v1909.194

Wipe data/factory reset

Bootloader, recovery, your in slot A

Apply the Android 10 ZenUI update, which ends up on slot B

Wipe data/factory reset

Bootloader, recovery, your in slot B

Reapply the Android 10 ZenUI update, which ends up on slot A. Both slots now have Android 10 ZenUI

Wipe data/factory reset

Go into the bootloader once more to get into slot A

Boot into the latest TWRP for Android 10

Swipe to allow system modifications

Check to make sure there are no mounting errors in the log

Flash the TWRP installer

Flash the latest Magisk

And your all done! Reboot to system.

Swipe to install the TWRP app on your way out

flashall.cmd is from the Sevice Firmware zip I downloaded from somewhere. It was in an unbricking guide, but It helps me by downgrading to Android 9, and setting up the partitions correctly again, in case they got messed up (which they have been throughout my testing)

The ZenUI updates I downloaded directly off of Asus's support page for this phone. You just have to pay attention to the fact that these are incremental updates, and need to have a specific firmware already installed in order to be flashed correctly (They say which once in the description). They also only can be installed with the stock recovery. (or at least, twrp never got very far when trying to flash them). I'd say just stick with the stock recovery for installing updates.

Speaking of TWRP, it has issues with restoring backups. It normally ends up with an error like "TarFork() Error 255", but apparently that can mean a bunch of different problems, so its not very helpful. I found that if you want any chance of the backup being restored correctly, you need:

- To be on the same Android version the backup is for (Android 9 restoring Android 9 / Android 10 restoring Android 10 / etc)

- Make sure TWRP doesn't have any mounting errors. This seems obvious, but most times, I had issues where TWRP couldn't mount a partition for some reason.

- You MUST have the option "Use rm -rf instead of formatting" enabled. I never got a backup to work without it enabled

Even after all that, sometimes the backup STILL wont apply. Once a backup fails to apply, nothing will work until I flash the service firmware and incremental updates again in order to try again. It's very time consuming.

Now, I don't know as much as I probobly should about linux or android, but that last option makes me tells me that instead of actually formatting / recreating the correct partitions, it just deletes all files and puts back the ones from your backup. That works great and all, but if the partitions get messed up somehow, the only way I know to restore them is by flashing the stock ZenUI updates in order (Service Firmware -> ZenUI v1906.167 -> Android 10 ZenUI). To add to the confusion, I'm not actually sure if TWRP backups/restores include both slots, or just the slot you are on. For good measure, I make sure to update both slots evenly, so that they end up with the same firmware version, however, I have only flashed one slot per update, and gotten a backup to work also. For example, instead of flashing each update twice, to get it on both slots, I have only flashed each update once, so that Slot A gets the service firmware, then flashes slot B with Android 9, then flashes slot A again with Android 10, and then restore, and It works. Its all very confusing and seems inconsistent. Maybe I'm missing an important detail, but I can't figure it out.

One last thing about restoring backups. I have a hunch that going through the first-time setup of the phone (specifically, adding a figerprint/pin) does something to the system or data partition. Whenever I was restoring a backup, I had a better chance of it working if I went through first time setup, and skipped adding a fingerprint/pin. I would then get to the home screen, and restart into recovery to restore.

Sorry if this is confusing to read. I'm kinda just dumping all my information for me or someone else to read later if they are as frustrated as I am now.

I wish it would all just work, or at least give more descriptive errors. Trying to google any leads I find reveal almost nothing. I feel like If I'm not a retired developer, there's no way to understand any of this.

Also, if you know how something works better than I do, or if I'm explaining something wrong here, please let me know! Really, I need all the help I can get on these topics.

Uh yea, so that's all I got. I have my fingers crossed that all the pieces can come together for this phone, but I know its going to take a long time if its going to happen at all. The Zenfone 7/Pro just got announced(released?) and maybe everyone will just abandon the 6 now. That seems to be the trend now anyways.