I was running SNAPSHOT version r23900-7f54d9ba1a / LuCI Master git-23.236.53281-98e3743 just fine. However, now that this hardware is fully supported, I used the Firmware Selector to download full version 23.05.2. I downloaded the SYSUPGRADE file, and then uploaded it via the LuCI UI.
Now, my device never came back online after the update. I selected to preserve configuration, but it isn't working. When I try to ping it, I get a 'Destination port unreachable' ICMP error.
The web UI simply doesn't respond, and my SSH attempts are rejected.
I don't quite know what to do now. This upgrade obviously didn't work at all.
Thanks. I followed the instructions to factory reset and I can get into LuCI now.
I think the problem is because the 23.05.2 build has HTTPS (TLS) enabled on the LuCI UI, and the SNAPSHOT image didn't even have LuCI until I installed it manually. I never added a cert or turned on the HTTPS access. This is just a hunch, however. I don't really know why the upgrade caused me to lose access.
Now I have to re-setup my router, but at least it's not bricked!