It is apparently a common enough problem that the game creators have a post about it:
Nonetheless, even if community server is selected on world creation, it might still not show up to other players. If that is the case, other players should first try to restart the game, and search for the server again.
This is to refresh the game, and possibly delete any previous cache that was gathered. Also, make sure that the creator of the server is online and, in the world, or server. Use the search field to find the server easily.
If you still can find the server, then have the creator of it restart the game and server. These are the only two options available to fix if servers are not showing up in Valheim.
For everyone who plays the password will be changed by tonight and given out upon request (for grg members/known and trusted friends of grg). Unfortunately items have been stolen and its possible a non grg member found the forums and loaded into the server and took them. By tonight with the new password we may also rollback the server to an estimated time before the items were taken but thats not definite yet.