I think its a glitch from the last update to fix bots showing as players or something. Valve as usual fixed 1 thing but damaged something else
lol
This is what they fixed last time ....
Engine
Fixed servers with bots reporting incorrect player numbers
Say you had a 24 slot server ( like we do ) and like to have it look like its got people on it even if its empty so you would add say 8-10 bots on there.
Now as people would join it would slowly remove those bots to make room for players. Something went wrong however and it still counted the bots as being present on the server so eventually it would say you had 34 players on a 24 slot server.
Now they fixed that bit but something is now up with real players. They leave the server but the server browser does not deduct those 2 players from the player count.