NE200 IP Passthrough
It seems NE200 Firmware doesn't really support clean bridge mode (via IP Passthrough).
I wish EN200 to work in bridge mode to provide internet directly to my Omada ER605 gateway WAN1 port.
I enabled IP Passthrough, specified the correct WAN port Mac Address, disabled NAT, DHCP server and made sure I receive a proper IPv4 from my ISP (not to be blocked by CGNAT). Still, ER605 can't receive the IP from EN200 (timeout). It seems to me that the NE200 firmware is a limitation, and the advertised IP Passthrough doesn't work properly.
The only way I made it to work is to keep NAT and DHCP "On" on EN200. However, that is not ideal as I have double NAT now.