Download TWRP for the U9 from here and rename the file to recovery.img
https://androidfilehost.com/?fid=employee monitoring software
Copy the above recovery.img onto the root of an SD Card formatted to FAT32, put the SD Card into the U9 and boot as you would for normal recovery, if all good you will be presented with the TWRP boot logo.
Once you have TWRP up and running I would recommend making a backup of your Data partition and then do a full firmware flash via USB Burning Tool, once you confirm you are able to boot into Android I would then use TWRP to restore the Data partition backup.
***You would need to backup to an external USB drive so make sure it is attached before booting into TWRP, ideally an SD Card above 16GB would be perfect as you could backup to there***
I did this tutorial for the U22 but it is pretty much identical for the U9 apart from the various additional partitions, have a read through for backup and restore:
https://drive.google.com/file/d/17NoduflXrKrvSI3E8aIX6wlDtVtgsV8b/view?usp=sharing
