Animal Crossing: New Horizons is the first (and currently only) fifth-generation Animal Crossing game.
Item duplicationIn version 1.1 (current up to 2020-3-26) and earlier, items can be duplicated by:
Placing outdoors an item, preferably of 1x1 size, which can have others stacked above (such as a cardboard box) Placing the desired item above said one Entering single-system multiplayer (which requires two controllers, two local users playing the game, and the Nook Phone "call citizen" feature One player shall then keep rotating the box in-place, while the other attempts to pick up the desired item (see video)
This trick has been reported to occasionally cause visual (and possibly functional) corruption, resulting in the item continuing to float even after the box is removed.
Villager moving glitchesUnlike in previous games of the series, the mayor can manage how many NPC residents their town will have and where they will reside, by pre-paying and marking the land for their home, then asking the desired character (from the camping lot, a ticket island, another town's leaving islander, or an Amiibo who has been summoned 3 times) to join, causing the land to be marked as sold and the house being built overnight. Villagers leave of their own will or by being evicted by the mayor when inviting an Amiibo in a full town.
In version 1.1.1 and earlier, asking another town's character to move in would result in the land being marked as sold but the character never actually moving in.
However related issues are still in the game as of version 1.1.4, as can be deduced from the following report:
I had [Raymond] on my 2nd switch, evicted him, and invited him on my 1st one, and he did indeed move. As soon as I went online, he disappeared! If I go to his house it says he moved away; I can't find him around the island (museum included); if I choose to move his home or send him a letter he responds, but only in these cases. I can't evict him, because it says the 10th house is occupied, so I'm forced to keep it that way.
These issues are not guaranteed to happen: they may be random or linked to internal factors.
Version 1.2, released on 2020-4-22, fixes the bug retroactively by scanning and fixing the save when first run.