I don't think you guys get how reserved slots work.
There's no way to know who's connecting if they're reserved or not.
It'll keep the 24th slot open until all other 23 have reserved slot holders.
Now if they are not, the 24th slot is allowed for a person to connect. If a person gets on and once their steam ID is auth'd and sent to the server, the server checks it against a list and
if good, keeps them and boots a non reserved player. If not, it'll kick him and let the next person que'd up in. That 24th slot is constantly a revolving door and there are always people with the auto join. Being reserved doesn't gurantee you'll be able to connect.
Next time goto the 2nd server and start getting games going there.