Remote Access says unreachable, even though it's reachable

[FayeInMay]

Hello,

 

I have a multi router setup, basically like the picture below.

Now I do have configured port forwarding from R1 Port 33443 to R2 33443 and from R2 33443 to UnRAID 443

I can actually connect to my WAN IP:33443, but unraid connect and unraid say the server is unreachable.

Do I need to pay attention to anything else in this specific setup? I mean it works using the external ip, but I cannot use Unraid connect as it doesn't recognize it.