1. It is still starting
A first start downloads about 4.3 GB and then builds the world. The server is listed once its log says "Started SourceServerQueries". On Flux the dashboard shows the progress, and the Console tab the log.
2. The filters
The in-game browser hides servers by default (mods, passwords, region, player count). Clear every filter and search the exact name.
3. The game version
An Enhanced server is only visible to the Enhanced game, and the other way round. After a game update, a server that has not updated yet refuses players on the new client; ours updates itself and warns players first.
4. Mods
A Legacy mod on the list can stop an Enhanced server from starting at all. Check the server log, and remove mods without the Enhanced tag.
5. Direct Connect
Direct Connect with the address and port bypasses the list entirely. If that works, the server is up and only the list is the problem.
Frequently asked questions
How long until my Conan Exiles server appears in the list?
About a minute after the world loads. A first start downloads 4.3 GB first.