I was able to recreate what I mention earlier with another item. I dropped a stack of sap and slept for a night. When picking them back up, the next morning and sometimes right after dropping, it looks like the game is thinks player is picking up multiples when picking up just one. The notification shows multiple when grabbing one, but when checking inventory, the number is correct, showing you picked up one. Its glitches when saving and loading after you have dropped and slept for a night. Possibly even not sleeping for a night but did not check. So it looks like the quantities are saved and then loaded officially into game after starting from save file. Just thought that would help.