Since September 12th, the links on websites (https://deutsche-arkserver.de/, https://www.battlemetrics.com/) or even on the desktop no longer work and generate the error message: "Failure: Unable to connect to server, app id specified by server is invalid". The links are all structured as steam://connect/<server-ip>:query-port>.
The error seems to have originally existed in the beta version of the Steam client and then been transferred to the main/standard Steam version with a minor update on September 11th, 2023.
URL with RUN
The game can also be started via Steam using the ID, and a server IP & port can be passed through connect.
The disadvantage is that the game itself must not be started yet. If the game is already running, it cannot be connected to the desired server/IP:Port (and no "error message" will appear) - at least in ARK Survival Evolved. So we should get a solution with "connect" directly from Steam again.
For each server, the following needs to be done once:
1. Close the error message, then the details will be displayed
2. Copy the "<server-ip>:<port>" (e.g. from our cluster 220.127.116.11:17000)
3. Open STEAM and go to "Game Servers" (View->Game Server)
4. Switch to Favorites (top) and click Add (plus symbol) at the bottom/right
5. Add the previously copied content with "ip:port"
6. Now the desired server will appear under Favorites
In addition to the main server "The Island" with Safebase (18.104.22.168:17000), the other IPs are available on the page Server (but in-game cluster transfer is not affected by this).