Hello,
I am experiencing very similar issues. With 24.10.0. Going back 23.05.5 solves the issue. No config change between one and the other. Device is a dummy AP without firewall, DHCP or routing. I removed wpad-mbedtls and replaced with hostapd-mbedtls, and same issue occurs.
For me, the 5GHz band dies, only 2.4GHz works. Only a reboot can bring back the 5GHz band, only to stop working again. Being reproducible with hostapd-mbedtls, I woudl assume the issue is not with wpad or hostpad, but with the firmware itself.
I see some other user also reported its 5GHz dies and rebooting brings it back 5ghz can't connect after 24.10 upgrade
So it is reproducible by several people using Xiaomi Mi Router 4A Gigabit Edition v1.
I would say the GL-MT1300 tested by bluewavenet is a different hardware even if both are mt7621, and that is why that device is not seeing the issue.
I will try 24.10.0 RC5 and RC6 to check as @fernandodiacenco pointed out, if upto RC5 works, and from RC6 onward breaks