Wave behavior seems broken/odd

My wife and I run UT together quite a bit, so it's a great test bed for the new wave format. However, I can't find any real consistency to the overall waves and either I don't understand it correctly, or there's a bug somewhere.

For the 7 waves, breakdown is:

Wave 1: The Berks - 1x-4x times. This is the most inconsistent wave. The vast majority of the time, it doesn't repeat at all. If it does repeat, it's usually 4 times. But sometimes it's only 2 or 3 repeats. This is really odd to me, as it takes very little time to kill these 3 mobs, so if whether or not a wave repeats is based on time from start attack to all NPCs dead, we should see a fairly consistent set of wave repeats, I'm guessing usually 2-3 repeats. Instead, it's like 90%+ 1 time, and infrequently it repeats.

Wave 2: Skeleton1 - 1x-2x times. Almost always 2x. The variability here is mainly due to the behavior of wave 1, as if we have a ton of Berks to loot due to 4 repeats, we take a long time on this wave, so I understand it not repeating at those times.

Wave 3: Skeleton2 - 2x times. Very consistent

Wave 4: Skeleton3 - 2x times. Very consistent

Wave 5: Lich1 - 2x times. Very consistent

Wave 6: Lich2 - 1x-2x times. This one is almost always 1x, but every once in a very great while, we get a repeat on it.

Wave 7: Lich3 - 1x times. Don't know if this one can repeat, because if it can, we've never cleared it fast enough to trigger a repeat.


So the behavior on wave 1 is the really odd one. Wave 6 is a little funny, but it's possible we're just really close to the timer and that's why sometimes we get 2 waves.

 

I figured it out ... The trigger that starts the timer for the first wave is not combat, but your location. At some point between the door and the cauldron area just before you go down into the larger cavern, the timer will start ticking.