Bug With Loot Cooldowns

So every time I log on there's a loot cooldown, which okay I mean I guess I can understand why they would need that, but the problem comes when the cooldown is over, usually, when the cooldown is over you can then go and start looting like normal but when I looting I get three sometimes four chests in before I get another five to ten minute cooldown, I was curious if there was a reason for this or if it's actually a bug I'm hoping it's a bug because if someone thought it was a good game mechanic and I'm gonna have to deal with I'd be pretty upset.

 

Hey! Please report bugs in the bug reports section!

 

I don't think it's a bug though

 

Higher tier chests have a longer cooldown; a tier 4 chest is like 30 minutes or so, but a tier 1 is like 5.

 

oh okay because I was doing a lot of tier three and fours