Bricked Volla 22 by installing Volla OS over Volla OS

[pnguyen9]

UBports Installer 0.10.0 (deb)
Environment: LinuxMint 21.2 Victoria linux 6.2.0-26-generic x64 NodeJS v18.12.1
Device: Volla 22
Target OS: Volla OS
Settings: {}
OPEN-CUTS run: N/A
Pastebin: https://snip.hxrsh.in/ubi-1692633081172

My phone was natively running Ubuntu Touch. I used the UBports Installer to install Volla OS, after which I kept seeing a message about unlocked bootloader. Following an advice telling me I could lock the bootloader by using the UBports Installer, I tried using it again. After enabling Developer Mode and USB Debugging, the installer was performing the procedure to install Volla OS (even though it was already installed) and rebooted into fastboot. Once done, the screen fadded to black, and now it doesn't turn on anymore.

[pnguyen9]

After contacting Volla, they suggested me to contact their partner from the following company to have my phone repaired: https://phone-service.de/r/volla/

I can confirm that my phone was flashed with a brand new VollaOS (and it's indeed my phone and not a new one I was sent). The only drawbacks being that they are located in Germany, so if you don't live there, you will have to send them your phone by mail, as well as the fact the entire process will be in German (you'll need an online translator if you're not fluent to understand the instructions).