Bug 1: Pregnant female dwellers randomly undragable once they become Pregnant...fixable by client restart.
Bug 2: When Raiders or Death claws attack some times they will be attacking one room but be physically in another forcing you to watch for damage on dwellers instead of raiders.
Bug 3: When in combat in a room dwellers move about and will stack up, if one is low health and needs healed but is not top of the stack they are unclickable and die at no fault to you.
Bug 4: Rooms that don't produce resources don't level dwellers forcing you to either not always have a dweller in them or simply never but instead dwellers are nearly all the time in one of 4 types of rooms unless raising a special stat. Storage and radio station both need to level up dwellers. Exception to this is living quarters as that if they assigned bring on something else.
Bug 5: Death claws. When attacking max lvl door isn't even a speed bump and they are right in at the first room...door needs to at least stall them for 10sec for dwellers to get shuffled to fight. But moving dwellers is all you be doing as the claws won't stay in one room longer then a couple seconds...gone almost as fast as it takes to drag dwellers.
Bug 6: Exploring serves little to no reason once all current dwellers are out fitted with outfit and weapon. Rarity dropped from exploring seem to only provide the very basic and thus lies the issue. Lunchboxes provide all the high quality stuff...forcing to race through challenges for rewards more then actually maintaining the vault properly.