I had tried too to add it to the pool (in a lot of ways), and just now figured what was wrong: you had to go in "Edit" in the pool, and check the "Active" checkbox, to allow more addition.
Now it's added to the pool properly.
Now it's added to the pool properly.
This was me in an image post.
I wonder if many pools are locked like this one was, but in any case, may be good to mentions this here.
unrelated thing: is the information in hypnohub.net/index.php?page=servermap just carried over from what the site was based on and irrelevant to us and the site, or is it really linked to this site?