Hello! I would like to see a screenshot from you, if you can provide it. Look at mine, this is how is it supposed to be in the game.
Can you give some information about your browser, this could be useful to understand what is your issue.
Cursor: 
So, is it working properly for you right now after restart? If pickaxe cursor doesn't work or somehow is bugged or something, for some reason, try this option then:
EDIT: I suppose I understood wrong, and you said that restart helped you. It should have been working normally as in every possible browser.