VPN Connection does not work

[hstruck]

The VP connection under "Network Services -> Network" does not work.
NAS: F5-221
TOS Version 4.1.15-1912051815
I have tried different connections with different VPN Servers, which are all working on my other Systems, but it seems to be impossible to connect to any of them from the F5-221.
I have even tried it with different TOS Version, to no avail.
This feature is very important to me and my older Synology doesn't have these problems.
So, what am I doing wrong?
When trying to connect to a VPN Server I always get "Connection failed", which isn't helpful at all.
At least it should say what went wrong. And it would be much better, if there were an accessible Log File.

[TMSupport]

Hi, please advise which protocol did you choose, OVPN, PPTP or L2TP. If it's L2TP, it may has this connection failed issue, and the engineers are working on it now.

[hstruck]

Which protocol?
All of them.

[TMSupport]

Is it allowed to let our engineer have a remotely check-in to get a clear idea of the issue and cause? You can send us an email with location and available time to support@terra-master.com .

[hstruck]

Sorry, but unfortunately that is not possible. The NAS is in my internal network and external access is not allowed. However, the NAS itself can access the Internet very well, but unfortunately not via the VPN function.

[sports_wook]

Any updates here? I've installed the VPN app to enable remote connection from other devices, and I can successfully connect to the VPN (using L2TP) but I can't access the internet or any of my files while connected over VPN. Any help here would be greatly appreciated.

[powerQ]

you better check if your external connection is blocked that lead to VPN connection failure.