Please help: How to access an upstream router that has local address

[ubear]

Hello
my OPNsense instance is downstream from my ISP modem/router, my WAN address is 192.168.1.17.
I want to access the modem configuration page at 192.168.1.1 from my VLAN 192.168.40.1/24.
How should I configure the firewall/interfaces?
Tried:
1. Removed the tick at interfaces->WAN->Block local addresses
2. Created a local rule at VLAN40 to allow access to 192.168.1.1, placed first after standard no-lockout rules.

Advice?
Thanks
Uri