We display 5 games max in a lobby sorted by ping time.
When Castle Crashers searches for a game for you, it returns a focused-random result -- it will give you 5 games that have good ping times, but not necessarily the same 5 games when you search over and over again.
This is why you can see GamerGuy1 hosting through one search, miss it on the second search, and then see him again on a third.
Don't worry, it's not a bug! We just want to spread the hosting love around!