Hey, thank you for the link. I tried using the sysupgrade.img.gz file and flashed it into the router from the web. After "Waiting for changes to be applied…" for about 30 seconds, the web just goes back to the router login page and when I logged in back, I still see the same firmware version in the status overview page.
What am I doing wrong? (I did try both keep current settings checked / unchecked, same result)
I'm not sure but I think the sysupgrade is only possible if you used a squashfs to begin with. if you used an ext4 image you might need to flash a new ext4 image. Take a backup of your config first through LuCI so you can upload it once you've done the flash.