GL-MT3000 LED keeps flashing after firmware upgrade

My GL-MT3000 Beryl doesn’t work after a manual upgrade. Its LED keeps flashing. I tried to reset it but it doesn’t help.

The firmware version is openwrt-mt3000-4.4.5-0811-1691754744.

Is there a way to restore it to stock firmware? :pray:

I tried to follow the U-boot instructions here. It works after a few attempts.