I use a glinet x3000 and was just about to set up a new sim card, when I got a notification for new firmware. I clicked on upgrade and waited for reboot. Except after 2-3 minutes it hadnt rebooted. I saw several lights were blinking. The internet light was lit and then after another the 2G and 5G wifi lights would blink. I searched for documentation regarding this and couldnt find anything. Therefore I unplugged the power cable (big mistake) - after all there is no issue which cant be solved by powering up and down.
Since then only the power light turns on when I plug the power back in. I tried the reset button for 10 seconds - nothing. I tried the debrick with uboot tutorial - didnt get over the step with the reset button.
Either I hold the reset button wrong or I just thoroughly bricked my router. No I was not using any custom firmware!