Delerium: Drops after time out takes 15-240 sek to drop

Hey GGG,
I’m having major issues after speccing my atlas for Delirium.
I get plenty of Delirium mirrors, but when the loot is supposed to drop, it takes an incredibly long time!
The fastest I’ve experienced is 15 seconds, the longest is 240 seconds.
The same thing happens whether I let the timer run out or click the “end now” button.
I’ve tried reinstalling my client—it doesn’t help.
I’ve tried different servers: London, Frankfurt, Stockholm, and Paris.

On some maps it works normally, so I don’t quite understand what’s going on.

Edit: If I teleport out of the map and back in, it doesn’t help either