Lenovo C13 Thinkpad can't boot in Dev Mode from Internal Disk

So, my C13 Thinkpad (3500C - NVME) cant boot in Developer Mode from the Internal Disk.

The symptoms:

Reboot in Safe Mode (Esc+Refresh+PW)
Ctrl+D to enter Dev Mode
Reboot After Dev Mode being set
Get into this screen:

Click in cancel makes the screen blink in to the reboot menu.

Reboot again in Safe Mode (Esc+Refresh+PW)

Only the option to Recover Whit External Media apears.

In Chrome://System:

block_devmode = 0
block_devmode_fwmp = 0
block_devmode_sysfs =0
block_devmode_system = 0

What I already try:

Reinstall the Chrome OS (to reset fwmp)
Reinstall an older version of Chrome OS (112)

I think on Discord you said RecoMod didn’t work? If you can get it to work, I wonder what would happen if you set the GBB flags to TONORM prohibited (blocks verified mode)

If you’re trying to flash UEFI though, you’re only chance might be to flash with an external programmer…

Well, when you asked about it I actually tough you’re talking about a clean reinstallation from the recovery mode, at the point I didn’t know that RecoMod was actually… a mod… Hehe

What is your end goal? Because I believe you can install UEFI with RecoMod as well

Since I don’t know anything about RecoMod, how exactly it work?

I think you would be soft bricked if you did that lol

Just for the question… how safe is this method? I mean, I don’t want to brick it, if is too risky I would like to sell it instead of have a tech brick on my desk.