jigsaw treasure hunter pieces don't move

There are a couple things I can think of that could be the issue. Firstly, the game might be frozen, which probably would be resolved after refreshing the page. Second, your browser may need an update, which can be accomplished via the three-dot menu in the top righthand corner of your screen. Your computer itself could need an update as well. The one other thing I can thing of is that you do need to actively click & drag each piece; if you were using a touch screen device, for example, perhaps a mouse or stylus could help.