If you notice that CORE is running very slow in your browser, you can try logging out of CORE and clearing the cache of your browser. Sometimes that can help to resolve browser-related issues. You can check the CORE Status site for an update and subscribe to them.

Please note that users who are using a trial version of CORE will be having slower speed compared to the paid/subscribed users because the trial databases are on the trial servers while the subscribed databases have dedicated servers assigned to them.