I think that there is something glitched with uber spawning. I've encountered this a bunch of times in free play, where everything is normal, but I get the message that an uber has spawned, when there is no uber on the map. I was playing on embankment and couldn't find the Ubers several times (there were three that should've been spawned, couldn't see a single one), but I pretty much thought nothing of it. The uber spawning does work sometimes, but other times, the message comes, but no uber spawns. I played on towhead, and got the message of an uber spawn, and could not find it, which is really strange (it is a very small map, and I checked all the enemy locations from the mini map). There was a similar report on steam recently, so I decided to post here, as other people have noticed the same thing, and not just on the embankment map, but also towhead (I haven't played on the Dunes, but I'm guessing that the problem may not be map related, just a general free play bug).