So it's just a display bug about the duration of the boost?

Well, at least, with your video, now I understand why I always see half of the bugs gold added to the counter: the other half is added after the map reappears (on your vid, 7000 for the boss, 3500 during the fight anim, 3500 on the map)

Man, 40 runs? How many gems did you spend to resupply your stamina??