Mouse gets stuck/stutters after left-clicking a friendly npc/player within range of your character. Similar thread on NA forums. It appeared after this patch. It’s not the raw input one that people also seems to have but a different one. How this happens is beyond me. Please fix asap.
EDIT: Also happens on targetdummies which probably means that it happens to everything you target. 4 of my friends on discord also has this happen, we’re using Logitec, Razer and Zowie mice.
EDIT: Can confirm that it happen on anything that you can target by left-clicking.
Here is a clip i found being linked on the NA forums that shows an extreme version of the bug. It’s not always this extreme.