There's this glitch where when you are level 5 and you attack a level 4 or levle 5....and before your troop reach them, you levle to level 6. Then your troop will just keep repeat from 0:03 to 0:00 infinitively. Until you click recall. And the recall time will equal to the time you waited.
For example: it took my troops 9 min to reach. I waited for the 30 min, when the bug occured. It took 39 min for the troops to come back (the time i waited + 9 min original time) when I click recall.... so WTF