The manual/Wiki is not very clear about that when using bridge-mode the LAN-port will be used both for:
1. WAN-access
and
2. LAN-access (to the router).
My view is that in Bridge-mode the following ports should be used:
LAN - for router access (only)
WAN - for Internet-access (only)
WLAN - Wifi could be used for router-access.
In this way both external router and management can be connected at the same time.