If you ever flashed some sort of custom software or firmware, you will have to install stock rom on your Lenovo Pad Pro 2021 TB-J716F. Just keep in mind that you will loose all data stored on your android tablet once you flash the stock ROM on android tablet.
Boot Lenovo Pad Pro in EDL-Mode. Now, there are two ways.
If Lenovo Pad Pro is fully booted: use adb command “adb reboot edl”
If Lenovo Pad Pro is off or can’t be booted: press the volume up button and hold, plug the usb cable into the Lenovo Pad Pro and PC and wait a few seconds
Now this should appear in your device manager:
Start the QFIL-Programm, it should detect the port with the same name.
Go to “Configuration” -> “FireHose Configuration”. At device type select “ufs” and tick “Reset After Download” then press ok.
Back in the main window select “Programmer Path” and browse to the ROM-Folder, select the file “prog_firehose_ddr.elf”.
Select “Content XML” and browse to the ROM-Folder, select the file “contents.xml”
Click “Download Content” and wait, may take a few minutes
After its done, this status message should a appear and the Lenovo Pad Pro should reboot.
And that is it, stock ROM would boot now on Lenovo Pad Pro 2021.