Have you tried the usual things such as clearing cache, cookies, history, etc?
Have you tried the other usual things such as logging out & in of game/browser/Facebook/portal/Google Play, switching device/internet source off & on, tried using a different browser, uninstall & re-install (but only do this if you have your game progress & player ID registered with either your email address or Facebook account)?
Are you using the most up to date version of the game?
If none of these suggestions assist you then you may need to lodge a support ticket with Pixel.
Have you checked out the News & Announcements section of this forum