I just bought this device tonight. I unlocked the bootloader in fastboot, enabled usb debugging and then flashed the available Magisk patched boot.img in fastboot.
This is where my problems started. I can't turn on wifi and the screen stays in portrait orientation, no matter what I change in settings. I have the latest stable and latest Canary Magisk Managers. I have installed both and when I initially launched them, they say they require additional setup, but I am guessing that it fails without internet access.
Which version of Magisk was used to patch that boot.img? Also, I do have root access, apparently, because I copied Simple reboot through mtp and it works correctly and gave a root prompt, when initially launched.
When I boot the tablet I get a message that about the orange state, The device has been unlocked and can't be trusted, device will boot in 5 sec, which appears to mean that dm_verity has not been disabled. When Magisk Manager is launched I do not see the options to check for encryption and dm_verity, as normal, or the the Safety Net check option, also.
With the patched Magisk boot.img installed, I think the first thing I will try is to factory reset to see if that will fix the issues.
Any thoughts will be appreciated. Everything seemed to be going well, as I had experienced on my Nextbook Ares 8A tablets, until all of this happened.
I just factory reset and it can't find any wifi networks. I guess I will now flash your stock boot.img. This make me wonder if this is a newer revision of the tablet, because I have several Nextbook devices and if I flash a boot.img from a different revision of the tablet, I will also loose Wifi.
I can easily return it as I now work in the Walmart Photo and electronics center of my store.
I guess this is a lession. I should have used your mtk root solution to back up the stock boot, assuming it is a newer revision of the tablet.
UPDATE: what do I have to loose? I am now also flashing your system.img to he if this will help.
On my 5 Nextbook tablets, maching system version with the same version of the boot.img works in all cases. If it fails, I will return the tablet and get a new one.