The latest update 3.4D under Properties>Betas>Beta finally solves the issue we were seeing where the second material in a blueprint would get set to zero.
I was looking in more recent scripts, since it appeared to be a new problem, however, it turns out that this issues has been active since Star Explorers was released in May of last year.
The reason it turned up now is that very few items actually use all the data slots like blueprints do. Only weapons and space suits would have been effected by this problem, and it makes sense that when a player finds a new weapon or suit, they would want to equip it as soon as possible.
The issue would only have effected items that were stored in the second row of the player's backpack, and then only when the player picked up items like crystals or ores, and they were alloted to the third (last) row of the backpack. Essentially data of these items was being written to the wrong slot, and it would set some of the items in the previous row's statistics to zero or otherwise incorrect values.
3.4D fixes this once and for all. However, any blueprints or other items that were already corrupted in this way will remain corrupted.
Now I can go back to expanding the game. Let me know if you have any questions or find any other bugs!