Here is a follow up on my situation:
I finally got my phone back today and according to the repair center, the motherboard was not working, plus they couldn't fix it (meaning couldn't re-flash it, maybe?). They replaced the motherboard.
I have now updated the phone to the latest firmware (.119, via FOTA), tried to reboot, shutdown, enter bootloader, enter recovery mode, everything seems ok.
Thank you all for the support!