Fairphone 5 bricked

[klt]

I think I made a mistake:

After installing Android 13 and then Ubuntu Touch on Fairphone 5, being scared by the security warning, I locked the boot-loader.
It does not want to boot anymore:

With fastboot I cannot do anything:

fastboot oem allow-flashing
FAILED (remote: 'unknown command')

fastboot flashing unlock
FAILED (remote: 'Flashing Unlock is not allowed')

fastboot flashing unlock_critical
FAILED (remote: 'Flashing Unlock is not allowed')

My local reseller in Zurich cannot help.

I have written a message to Fairphone support on Tuesday
but I have not received any reply.

What can I do?
Any ideas?

[Lidwien]

Perhaps you are able to chat with support. The live chat is open on Mon - Fri: 10:00-12:00
You can find the chat at the bottom of the Support page.

[yvmuell]

just for the records: NEVER EVER lock the bootloader AFTER DOWNGRADING the security patch level which happens when you install A13. I would guess that Ubuntu does not support to lock the bootloader? @oli.sax pretty sure you know this

[oli.sax]

@yvmuell

Ubuntu does not support to lock the bootloader

Correct.