[General Questions and Answers] cheger32:
This issue happens to me. Going into settings and removing the screen lock solves it (but obviously no screen lock). Formatting data allows you to use a screen lock for a while, until the issue decides to pop up again. Usually though it followed doing something like installing xposed framework or something advanced like that. But other times it seemed it may have been a result of booting my custom TWRP image. It's built from a generated device tree so it's not perfect yet.

Edit to add: I modified my fstab and removed the metadata encryption entry for userdata. I haven't seen the issue appear since. Encryption is now gone, but this thing is pretty weak as it is and I don't generally keep data that needs encrypting on it.

Edit: "SystemUI has stopped working" is solved with the latest firmware. If you can't get latest firmware (The alcatel mobile upgrade tool kept telling me I was on the latest or it would just crash) Do a google search for MTK Sugar Tool. Versions after 2018 will force the latest updates to the device over usb

Now for a better bit of info I have:

Bootloader unlock and proper Magisk root is possible on this device. In order to get to fastboot to unlock bl:

1. If you have basic experience with python, you can use this script to boot to fastboot:

MTK Bootseq: enter alternative boot modes in MediaTek-based smartphones

MTK Bootseq: enter alternative boot modes in MediaTek-based smartphones - mtk-bootseq.py

gist.github.com

2. RISKY: If you are inexperienced, need to unlock bl, and have good AV software (This is how I did it the first time, but be warned: while my up-to-date installation of Kaspersky found nothing today (10-31-21), Virustotal.com showed that around 18 databases flag this program for trojan like behavior):

Search google for "MTK Boot Mode Selector Tool by mvirus team". There are several links available all over shady blogs and such. This tool does work and is a simple exe, requiring only that proper alcatel USB drivers and fastboot drivers are installed; However, it's sketchy as hell and I suggest you read up on python and just use the first option.

I AM NOT RESPONSIBLE FOR DAMAGE CAUSED BY POTENTIAL VIRUSES IF YOU USE THE SECOND METHOD

Use either method (but you should really learn how to run python scripts and identify the path or name of serial ports in linux or windows (respectively) and use the first method) to get to fastboot and bl unlock like normal.

In windows it's just a matter of rebooting your tablet while holding volume down and watching in device manager for the correct COM port number to enter as a parameter of the command. (I.E. COM7.) Once you have the port number, you send it to the script as a command.

I.E.:

python mtk-bootseq.py FASTBOOT COM7

To get the port number in windows:

My tablet rebooted three times and reconnected while holding the volume down key. Each time it reconnected, a new entry in the device manager named "Ports (COM & LPT)" appears. This will disappear as soon as it disconnects, which seems to be after something like 3 seconds, so you have to be actively watching. If you expand "Ports (COM & LPT), after the first two boots, "MTK USB Port (COM*)" will appear, with * being a number (I.E. COM7.) On the third boot, "Preloader USB VCom Port (COM*)" will appear. This is the COM port number you are after. It will likely be different than the port number of the first two, which were identical for me.

I may make a full tutorial on both the linux and windows python methods soon (though it's pretty simple if you have basic experience with python,) but it doesn't seem like demand for bootloader unlock on this device is very high. (I have put a lot of work into this post already, however.)