It's my first time trying to configure a VPN, I am clearly missing something and hope to have some help on that

The scenario is simple: I have a main router from my ISP and connected to one of his LAN port an Asus ZenWiFi AC Mini (with 2 more nodes). My home network is working perfectly.
I wanted to access my home network from outside so I setup the OpenVPN feature of my ASUS ZenWifi router like that:
Code: Select all
Interface Type : TUN
Protocol : UDP
Server Port : 1194
Respond to DNS : Yes
Advertise DNS to clients : Yes
Encryption cipher : AES-128-CBC
HMAC Authentication : SHA 1
Compression : Enable
Username / Password Auth. Only :No
Authentication Mode : TLS
RSA Encryption : 1024 bit
Extra HMAC authentication : Disable
VPN Subnet / Netmask : 10.8.0.0 / 255.255.255.0
Push LAN to clients : Yes
Direct clients to redirect Internet traffic : Yes
TLS Renegotiation Time : -1
Manage Client-Specific Options : No
I installed the client on my android phone and my windows PC, configured it with the file downloaded from my router (after changing to my dyndns address), and everything connects right away.
I do have access to my local home network (I tried a local webserver with his local IP address), but I have no connection to anything outside my home.
Any idea what can cause this? Can it be the port forwarding mis-configured? firewall on the routers maybe?
Thank for the help everyone!