Sounds not good. But, numerous people I've read indicated when doing this not all lun's flash, but after doing all they could, it finally booted.
so one thing, the phone can be put in edl mode from any screen. Even if it's blank. When u plug it in, does it show the battery charge indicator? I've waited for that to almost completely finish (showing the circle and %), then press and hold all 3 buttons and when screen blanks start spamming vol up.
essentially, you can't brick a v40. Some I've read have opened the device and shorted the pins in the back, to get to edl. Personally, my device has always responded per method above.
Yeah the unfortunate thing with the backup is that after ea lun is flashed it reboots, so have to go back to edl for ea lun.
I have the xml setup to flash everything at once for at&t Q, but have only used it with the bkerler edl python utilities. It works, if u want to try it. But like all these backups, it does not contain (nor should they) the ftm, fsg, modem, modemst1, modemst2 partitions. Those contain your imei and s/n info and should not be flashed to a different phone.
good luck