M2 MR2100 QNAP VPN and AFP issues

When I hotspot my MacBook to my iPhone I am able to connect to my QNAP NAS via the VPN (L2TP) and Connect AFP to view my files and backup my computer over Time Machine but when I connect my MacBook to the NightHawk M2 I can connect to the VPN but I cannot connect AFP. I'm thinking it's something todo with the VPN connection because when I try to use my NAS local IP address it doesnt load. 

I have VPN Passthrough Enabled on the M2. 

What would be diffrent between my phone and the LTE modem? - Both Telstra. 

Any Suggestions? Probably something simple I'm missing....