I found out that the game will delete up to 10 items from your stash if you open the stash with a lower level character. Because your higher level characters usually have 40 stash slots from the tech upgrade and lower levels start with only 30. So if the stash is full when you open it on the low level character without the Tech upgrade, the difference of 1-10 items automatically dissapear. They don't re-apear when you log back on the character with the stash upgrade either. They're just gone.
I lost quite a bit of items, potential credits and materials before I realized. I hope this helps other players before they do the same thing.
I lost quite a bit of items, potential credits and materials before I realized. I hope this helps other players before they do the same thing.