That is definitely not normal. The first thing I’ll say is that you should not need to put the unit in hibernation mode every time you’re done using it. We’re actually going to rename “Hibernation” to “Shipping mode” because a lot of users have had this confusion. The batteries should last over a year with the radio on in a connectable mode.
My suspicion is that you found a bug in the hibernation mode of the latest firmware. I’ll investigate it, in the mean time if you could replace the batteries one more time and not worry about hibernation mode, it should work fine for you.