You can see it in the video in 5 seconds
@ThomasHH-DE I would just suggest taking a break, we shall see tomorrow, when khadas team is back in the office,
Guten Tag!
I have tagged him already 
thank you buddy!!
So now I’ve tinkered a bit again. I had VIMx.Ubuntu-xfce-bionic_Linux-4.9_arm64_V20191231.emmc.kresq installed and LTE worked great on Ubuntu:
Then I installed the firmware VIM3_Pie_V191122 again and lo and behold, - LTE suddenly worked. BUT: LTE is shown to me, but I cannot use it system-wide. There is no connection to the Internet. When trying to configure an “Access Point Name”, I fly out of the menu.
As you can see in the video, the mouse operation at the top of the screen does not work at all.
after activating, restart the system again and try again
Yeah that is a problem of android, it will only give response if it is touched in the correct area,
So I guess the LTE modem works successfully ! sort of maybe 
you might want to update your data pack 
yes, you are somewhere nearby, do you have any understanding?
And you say it worked with leez board, with no problems !?
Sorry, - but the translation makes no sense. Can you put it differently?
Yes, it works great with the Leez. Unfortunately, it has too little memory
He is saying," you are close to the solution, do you understand it ?"
As before I am saying the same thing again 
I hope you can understand Guten Tag without translation, pardon my miniscule “deutsche” knowledge
Ah, - ok, - yes, I understand that 
But if I consider that the modem was only recognized after a few days, then I believe less and less that it will ever really run smoothly.
It is only temporary problems, it shall be fixed with a simple OS revision handled out by Terry
probably by the coming week
OK, - closing time for today
Thomas, don’t worry, tomorrow there will be the main Khadas team, probably they will have fresh thoughts on your problem
thanks buddy for clarification