Problems with GL-MT400N-V2 and VPN

Good evening,

I have the same problem with many users as I’m navigating the GL-MT400N-V2 router and Huawei E3276 modems (external home devices) FritzBox7490 (internal home device) router, which has a DDNS synology connection an OpenVPN connection to GL-iNet GL-MT300N-V2. I have three problems:

1-Every modem ip update update vpn remains connected but does not go to Intenet at least that it does not make Apply to vpn configuration and reboot the Internet. How can I fix this VPN automatic update? (I’m saying I’m not very familiar with this router so I’m looking for a detailed explanation).

2-How come when I do the sppedtest of my connection I can not exceed 7 mb? While I do it with my cell and VPN over them?

3-How can I solve my DDNS problem on Synology and access it when I’m out of the house?

Thanks Lollo9710