flashing stockrom on a “Lenovo Tab4 8 Plus” in EDL Mode

I have tried to install TWRP and LineageOS on my “lenovo Tab4 8 Plus” and it didn’t go well.
Now I have a brocken device… no function, only conected with PC and its a Qualcomm Device in a Diagnosis Mode, or when I change the Driver its Qualcomm HS-USB Qloader 9008. How ever I change the driver or try all possible tools like MiFlash, QFil or Lenovo Rescue and Smart Assistant it doesnt’t all help and no flashing possible. Do guys have any Idea what coul be wrong?

I thank you all