I was able to upgrade from the very old stock version to a release candidate of 23.05 (I think it was rc3?). This worked a lot better but had a few issues with ipv6 (Luci was unresponsive to setting a static ip and prefix for a machine).
I updated to the release of 23.05.0 and Luci refused to respond (Browser returns: "Unable to connect"). I know the router is still responsive because my static ips still work, networking works, and I can ssh into the router. I flashed a fresh version of 23.05.0 and Luci also refuses to respond at the web url.
I also noticed that while Openwrt is now on 23.05.2; the listed version is still at 23.05.0.
Is this a known issue? If not, how can I provide debugging information?
Go ahead and upgrade to the latest (23.05.2) using ssh. Do not keep settings when you do the upgrade (use the -n argument) and be sure you are connected by ethernet. This should make the device work normally by ensuring it is running the default configuration.