Not sure of actual voltages..
To be honest, not knowing the voltage of the cells makes this a little tough. As Monocrom said, it's possible that you received a bad cell(s) with the 2015 date.
If you don't already have one, a cheap multimeter, test cables, and a resistor makes a great CR123 tester (with a resistor in parallel, it will test it under load, not just its resting voltage). I test ALL of my CR123 cells before they go into any lights. This is especially important in multi-CR123 lights. If one of my
new CR123 cells happens to actually be bad, it could create explosive results in a multi-cell light.
Here is a good thread on testing flashlights, batteries, etc.:
https://www.candlepowerforums.com/threads/236906
-Robert