Flint GL-AX1800 uboot stuck

I have a similar issue. I have not used my AX1800 Flint router for some time and when I started it, no DHCP servers comes up. I took the following steps:

  1. Tries to reset either by 3 secs or 10 secs as detailed in the manual. I would still not see the router, neither via wifi or connected to my local desktop through a direct ethernet cable.

  2. Update uboot according to this answer: Flint (4.x) update brings down my home internet for hours! - #3 by hansome. That is update uboot from 192.168.1.1/uboot.html. This seems to work; the router blinks quickly, but then enters some sort of loop (more than 10 minutes).

  3. Reboot and use 192.168.1.1/ to upload firmware 3.216.

  4. After this the router enters what seems like the above mentioned infinite loop. The light is constantly on for ~30 secs, then it blinks once and fades slitghtly. This repeats forever.

  5. The DHCP server is not up (192.168.8.) network, neither is 192.168.1

Any suggestions how to fix this?