Android-x86 stuck at black screen and a static underscore _

I have a very similar problem to e.g. here.

I installed Android-x86 on a partition on my Acer Aspire Switch 10E next to Windows.

I added Grub as trusted boot option in the UEFI and let Secure Boot enabled.

Using this I can completely boot and reboot into e.g. Android x86 version 8.1-R2

But the problem is: in this version my Realtek RTL8723BS is not supported -> No WiFi/Bluetooth!


So I worked my way back to older versions (I need at least Android 6.0). Using CM 14.1-R2 and Androidx86 7.1-R2 I have a strange behavior:

Right after the installation if I select “Run Android” everything works fine, it boots normal, WiFi/Bluetooth everything fine!

But I am not able in any way getting it to run again after a reboot. It is forever stuck on a black screen with only displaying a fix (not blinking)

_

I already searched for two days and tried a lot of parameters and settings in the Grub entry like nomodeset, xforcevesa etc … nothing worked so far.

I also tried both 32bit and 64bit versions (the device is 64bit) but it made no difference.

I don’t understand what I am doing wrong or why it boots all fine the first time if not going for the reboot but directly to the Run Android option. So I guess it can not be due to unsupported hardware since the system basically works … I just can not boot into it anymore after shutting down / reboot.


Does anyone have a solution for that?


Note: I am not speaking about a Virtual Machine here!