Lazy reported to me ingame that when she trained at a map for a long time, she found that drops started disappearing too soon, about 30 seconds after they dropped. She says this has been happening since the Anniversary patch.
I'm not sure about this, but I've experienced it as well. After training straight for 2 hours, the drops did disappear a tad bit faster than usual, but not as quickly (not 30 seconds, but maybe 40-45?)
