Hi there.
It could be a caching issue. I would suggest you try a "hard refresh" on the page where you are having problems.
This is done by pressing CTRL + F5 (PC) or Command-R (Mac) on that page. Often, this will resolve the issue.
If that doesn't work, will you let me know what web browser and version are you using, please?
When I click a piece to move on either the daily puzzle or in live chess (haven't tried tactics yet), the piece won't move to the space I try and place it. And then it just follows the cursor. Any ideas why?