So this is a issue I remember being there for a long time, so I'm sure some people have been reporting it already but I didn't see too much mentions of it.
If you right-click during a loading, your right and left click actions in-game get swapped (or something similar, you cannot pick up items and only examine them instead). This is especially frustrating as it makes you unable to use some items, sometimes frenetically clicking can reset it to normal, but sometimes you need to disconnect and reconnect. This bug is fairly consistent, happens to me pretty often as I tend to alt-tab during loading and come back by clicking on the game.
Hope that helps !
Click on the screen during a loading.