Title says it all -- when using robots + deconstruction planner, if the miniloader has some items in it they will be destroyed. For example I have a chest -> loader -> loader -> train. I put 100 iron plates in the chest. There's no train there yet, but the plates start moving through the loaders until they stop. I deconstruct the whole setup and find that I only have 89 plates in my pocket. (My personal roboport is the only one in the game so I know the plates didn't end up somewhere else)

I've tested it several times and it's very consistent: Belt -> Loader -> Chest, when deconstructed, will destroy 6 items. Chest -> Loader -> Loader -> Train destroys 11 items (I guess it's 6 for each chest, but 1 item was held in the "inserter" ready to put onto a train when it arrived so that one was saved by the robots?)

What is supposed to happen is that any items that your construction robots can't fit in their inventories is dumped on the ground as loose items and those loose items are also marked for deconstruction, so your robots will reclaim them as well. This works for me in testing, so there's probably some mod conflict. Can you provide a save that exhibits this issue?

https://gfycat.com/heavenlygivingcentipede

That's strange. My game has a ton of mods, but I think the only relevant one is bobs logistics. I made a test game with only miniloader and no other mods, and it still destroys the items. I did exactly the same setup as you have in the gif and after putting in 100 plates I end up with only 88 after deconstruction.

How can I upload a save file?

Make sure you’re running the latest version of the mod, because the test I ran was straight from a new download from the mod portal. You can upload your save zip to any website that allows that (like Box, Google Drive, etc.) and post a link here.

Make sure you’re running the latest version of the mod, because the test I ran was straight from a new download from the mod portal. You can upload your save zip to any website that allows that (like Box, Google Drive, etc.) and post a link here.

Okay, I hope I did this right:

https://drive.google.com/file/d/16gD0TYrRMjPT5FawsaMm8TAfj7Enwgv3/view?usp=sharing

I tried deleting the mod and reinstalling it but the issue persists. Let me know if my save works for you or not. Should I try uninstalling and reinstalling Factorio?

Okay, I'm dumb. I was accidentally testing against an older Miniloader version. Should be fixed now. Oddly no one else seems to have noticed this in any version since the bug was introduced in v1.14.3.

Thank you, it works great now :D

Maybe most people aren't as OCD as I am, that's probably why nobody else noticed. I found out because I have a perfectly balanced system for shipping fuel to my several nuclear plants from one central processing facility. A train takes exactly 200 fuel to a plant when needed, and brings 200 used fuel back to be reprocessed. I was working on one of the plants and I moved the loaders over a couple of tiles to make room for a water pipe. The next time the train went to that plant, I noticed the reprocessing centrifuge ended up with 8 spent fuel -- 2 short of the 10 it needs for a cycle. It took me a couple of hours to investigate, going back to old autosaves and counting what was at every plant, but I finally worked out where the problem was.