I had the same thing happen a while back, we were on 2.1 at the time. I thought I’d imagined creating the perfected heavy padding but I checked with another player and they had seen the padding in the bench the night before I moved the Garrison bench.
Following up on this. I haven’t tested the heavy padding specifically yet, but today I rearranged my entire massive base (involving constant “pick up” actions). I didn’t keep meticulous track of all of the items that I had, but I lost several items including a coin mold and a casting bench, a bunch of dyes, all my twine, and some perfected heavy padding as well. I don’t see any reference to these items in my event log (even looking specifically for “Loot Bag” and “Friendly Inventory” entries. Inside my main base I don’t have any blacksmith benches, so all of these items were picked up from chest and benches that were not Blacksmith benches.
EDIT: OOF Lost an Entire Set of Epic Hyena Armor too…come to think of it, a lot of the stuff I lost may have been on the Garrison Armorer bench at some point…
TLDR: It seems like “pick up” is not always returning all of the items to the owner’s inventory. Will post again if I find more info.