I’ll make a start, but there is a lot unclear in your message. You are referring to two routers, a windows box and a phone. I assume the log that you post is from the ddwrt router, not the mt1300 router. It would help if you would explain where the ddwrt router is and how it connects to the internet, where the MT1300 is and how it connects to the internet, where the windows box is and where the phone is. And then what IP addresses exist in all this.
If I follow, you have an MT1300 in one place. Devices that connect to its LAN via ethernet or wifi will pull an address in 192.168.8.xx range. On its WAN side it will get some address and all devices on the LAN will have access to the internet. Your ddwrt router is in a different place, and devices that connect to its LAN side will pull an address which must be in a different range, and it will have a WAN address that must be publicly routable (or has port forwarding in place). That WAN address must also be unique, so the WAN address of the MT1300 and the WAN address of the ddwrt can’t be the same. Addresses like 192.168.1.1 are often issues.
When a OpenVPN client running on the MT1300 connects to your OpenVPN server, the MT1300 will get another IP address along the lines of 10.0.8.xx and your OpenVPN server will (1) add a route from itself to that address or (2) change the default gateway of the MT1300 to the OpenVPN server itself. If it does (2), then your phone will connect to the MT1300, and its internet traffic will be routed over the tunnel to the ddwrt router, and it will then send it out to the internet. It sounds like your windows box is doing that–is it?
If the server doesn’t do (2), then the MT1300 will send internet traffic out over its original default gateway.
Now, in the log, it doesn’t look like a connection is being made, because the server is expecting a TLS key that it isn’t received. Is that key in the .ovpn file?