Cyrodiil Delve Bosses are not necessarily on a timer. Well, there is a timer, but it does not work like you think.
It's more that only one can be up at a time. So, if the boss you want is not spawning, go kill the other one(s) and go back until the one you want spawns. The spawns are random so you may get the same boss spawning over and over again. I think it can work like Public Dungeons in the base game in that the first time you go in, you can have all or some of the bosses up, if no one has been in the delve in a long time. But, I don't think you would find all bosses up very often, so you have to keep killing the other ones to get the one you want.
The timer can have an effect on how long it takes the next boss to spawn after killing the one that is up, but it is not very long.
Now, all this being said, some delve bosses are just shy and can take a long time to spawn.
I know when you kill one boss that the other should "revive".
But in this case it was in 2 caves, both 2 bosses. 1 already killed by me, and the other boss doesn't respawn. I was pretty lonely in that cave, that's for sure.
I know when you kill one boss that the other should "revive".
But in this case it was in 2 caves, both 2 bosses. 1 already killed by me, and the other boss doesn't respawn. I was pretty lonely in that cave, that's for sure.
Did you go back and see if the first boss spawned again? That would be the first thing I would check. I had one delve where we had to kill the same boss 4 times in a row. It took a few minutes for that one to respawn too.
Yes, even though you have to kill the other bosses to get the one to spawn, they don't always respawn quickly. Then I have gone back to the same delve on another day, and the bosses all spawned quite quickly. It might have to do with how many players are in the cave, or the phases of the moon, or whether your dog likes you that day.
I think there are a couple that just don't spawn all that quickly, but ZOS has seemed to address this on most. At least I have not seen as many threads about Boss spawns in Cyrodiil as I did in the first year the game came out. There were a couple of Bosses that people camped for hours to get back then.