Today I tried to upgrade my R7800 from 22.03 to 23.05-rc2 using the factory image downloaded from official openwrt here:
https://downloads.openwrt.org/releases/23.05.0-rc2/targets/ipq806x/generic/openwrt-23.05.0-rc2-ipq806x-generic-netgear_r7800-squashfs-factory.img
I have not tried the sysupgrade image as I do not want to risk bricking the router without asking first.
I upgraded from Luci. After uploading the above image I get the usual red warnings. I unticked save current configuration and ticked force upgrade. This procedure to upgrade from 22 to 23 worked with my other Linksys routers (MR8300 EA8300).
The R7800 takes the upgrade, but then it reboots to 22.03 with its configuration unchanged. Clearly the upgrade fails, it is good that the router is not bricked or the configuration isn't even reset, but I cannot see any error using this method, therefore I have no clue why it fails to complete. Is it correct to use the factory image upgrading from 22 to 23?
Any suggestions?