RT-AC68U Port Forwarding Problem

Hello,
First time Poster here hoping to get some help. First my current specs:

• Router AC1900 [RT-AC68U]
• Firmware Asuswrt-Merlin 380.66_6
• CFE 1.0.2.1 (Asus)

I managed to get the asus CFE and custom firmware on the device by following the excellent guide here.
I had an issue moving from tmobile firmware to Merlin after initial CFE update, this was resolved by...

RT-AC68U Port Forwarding Problem