On new build (snapshot) via https://firmware-selector.openwrt.org/ the radio 2 (wifi7 6Ghz) is broken since about a week. It was working fine on previous build but those build doesn’t fonctionne well anymore as the opkg repos have been deleted and those build only support opkg… Sadly I updated and couldn’t rollback to a previous build.
I flashed my r4 yesterday with the current snapshot (used the firmware selector, tapped customized and added luci and iperf3 as well) and all 3 radios work for me, even 6g (with Macbook and iPhone as a client).
Only tweak I had to do: You need to set the wifi password encryption method to WPA3 - at least on the 6G band. Also I had to make sure the bandwidth was inside the allowed range for my country (eg in Switzerland 320 MHz as bandwidth did not work. Set it to 160 MHz and I could connect)