Hello,
I have just created the PR https://github.com/openwrt/openwrt/pull/22259 that adds support for the Cudy M3000 with the Motorcomm YT8821 PHY. The PR is working fine on my M3000. However, the PR includes a patch for the YT8821 driver that might also affect other Cudy routers with this PHY (at least the new WR3000H). Cudy routers with the RTL8221B PHY shouldn't be affected.
Would anyone be comfortable trying the PR on their device? I am mainly interested in whether you get a stable gigabit link on the WAN port.
My hope is that the patch will only improve the YT8821 behaviour on these routers. At minimum, the YT8821 on the WAN port should now keep on working even if you bring down the SoC-to-switch link on some of the routers (eth0 on my WR3000H with the Realtek PHY).
Best regards
Jakub