This is only the case in creative mode because, in creative mode, the item is not consumed when you place it in the shelf, but the shelf still drops its inventory when broken. This seems like intended behavior to me, as lecterns and chiseled bookshelves do the same thing
Upon further examination, my response has changed. It is always the right side of the chest that does not update properly
Not sure what the procedure it for updated information, but I have done a bit more testing following Graymagic27’s response. It seems as though the comparator on the side of the chest the copper golem placed the item in does not update properly, whereas a comparator on the other side updates fine, in order to reproduce the bug, I recommend using a setup like the one in the attached image.
For the positive values in the attack speed table, they all also show up when placing a period (decimal point) behind the number (trident also shows up for .9), and also with a “2.” behind it or a “-2.” this implies that what the search results are showing are the modifiers on the tools, A trident shows up for “-2.9” because it’s 1.1 attack speed is 2.9 less than the base 4 attack speed, this explains why -1, -2, and -3 have results, as they are the whole number attack speed values. searching 1 (or +1) attack damage shows 2 attack damage weapons because they have 1 more than the base 1 damage