I recently updated to RUTX_R_00.07.02.4 firmware. While many things have improved, bridge mode is still unstable. I have Internet connectivity for maybe 30 seconds before my Asus RT-AX58U router loses WAN connectivity, complaining about a DHCP issue - "Your ISP's DHCP is not functioning properly", changing to "Cable disconnected" when the RUTX14 goes away - (crashes somehow?). NAT works just fine.
I have tried changing many settings, MAC cloning, and even disabled IPv6 for the modem interface and Asus router just to reduce the room for incompatibility.
Is this a known problem? Some steps worth trying?