I had this.
The workaround on here...
http://forums.obsidian.net/topic/86659-quest-mode-reward-bug/?p=1807931
Select one of the other chars before hitting the blue continue arrow stops it happening.
Dx
Ditto
2 chars going l1 to l3 work ok
2 chars going l3 to l5 first reward card disappears off screen
Gold didnt show first time but does now.
No way round but to quit
Ios 9 ipad 3