I can't remember what version this started in, maybe around 1.0.6. Previously, I would sort my inventory when loading it or managing it by swapping & dropping from a chest, I would establish an order in the inventory you carry. When I close the chest, it stayed the same order. This is helpful if you want your rapid pick bar at the bottom of the screen. So you can pick up the right weapon quickly. Unfortunately, some time back, this stopped being consistent. I close the chest and look down, and the inventory is randomly scrambled. Sometimes, it shows a duplicate item, which is only in my personal inventory once, but shows on the rapid pick bar on the bottom more than once. This also happens when I ride a horse. When I go into horse inventory to put on the saddle, it scrambles the quick pick bar (and personal inventory when you open it). The problem is that sometimes I can't even be mounted on a horse and select the bow, because whenever I switch to the inventory on horseback and put the weapon up front, then I close it and it's not available. Going back and forth multiple times to fix this sometimes eventually fixes this, but it's like the inventory scrambles randomly when you open the horse inventory. Getting off the horse, fixing the inventory and getting back on does not work, because if I leave the saddle on the horse, then get off the horse and get back on, it does not go where I want, as if it had no saddle. So I open the horse inventory, take the saddle out and put it back on, and then I control the horse, but don't have access to the bow, for example.

This did not used to work this way, not it does. I thought maybe it happened because I have an old world taking up a lot of memory. I thought I noticed it in other worlds that don't have as much memory, but checking just now, the less developed (less memory hogging) worlds, don't seem to have this problem.