What branch? Im assuming this is on CL#98904?
I was unable to replicate this issue (on CL#98904). I tried saving, and re launching the game with 8 in hand, and 8 in bag. all 16 are still where they were pre-save.
(1) Is it possible you placed them somewhere else (like a chest, in the world, or as Fox noted, moved from bag to hand) and forgot or did not realize?
(2) Can you make a few more and attempt to replicate the bug on your save?
(3) did you quit to menu, or desktop. and did you click "continue" when loading, or manually pick the save?
(3b) If you manually picked, is it possible you unintentionally loaded an auto-save and not the manual save file? (or alternately, accidentally saved over a different save file than intended)