As it sits, this configuration implies that 192.168.18.7 will be listening for an internet IP of 192.168.18.7 to talk to it (talking to itself).
One thing I can see on my side is the IP address you talk to us from (both internet and internal IP’s). There are no 192.168.x.x schemes being reported to us with regard to your core or any connected device (like your Node). The 192’s are from Huawei and the 10.x.x.x are from Airport.
You may need to seek advice from your ISP to finish this off but here is the gist:
You need a forwarding rule on the Huawei that says incoming requests via your internet IP 38.25.x.x on port 55,000 get sent to your airport. When you do this, it will facilitate the connection to 10.0.1.27 (your core).
In your screenshots, it looks like you’re doing this in port mapping and that is correct. I found a video that is non-specific to Roon but is a general overview of how port forwarding is set up.
Wes