External connection fails but internal works

[TheNewJavaman]

Hello!

TLDR; Internal IP connection works, external IP doesn't.

I just set up and tested my VPN setup. My Android phone can connect to the server using the server's internal IP address successfully, but using the *.softether.net DDNS address or my public IP doesn't work. My Samsung S9 shows the message "Unsuccessful." I pinged my DDNS address and it showed my IP address successfully. I have port forwarded SSH/web services in the past in my router, so I tried that as well (ports 443, 992, 1194, 5555, 500, 4500, both TCP/UDP for all), in case NAT-T doesn't work with my consumer-grade router. I pinged each port with Netcat to verify that the connection is open. I know that the VPN server is set up correctly. My client can connect, so the issue must be with my router. Is there a step that I missed for external connections?

I would really appreciate any help. If my phrasing doesn't make sense, please help me find the right words. I'm new to this stuff :)

[gogotha]

Check if your router supports VPN pass-through or see if protocols gre 47, ipsec-esp 50 and ipsec-ah 51 can be allowed.

[TheNewJavaman]

Thank you for your reply. Update: the VPN works, so long as my VPN Manager application is not logged into the server. Do you know why?