When i click on a stock item and click run report nothing happens just lags the whole time what can i do?

I'd be glad to help keep your QuickBooks Online run smoothly, sales256. 

For the best performance, it's generally recommended to use Google Chrome. If the issue persists, you might want to close other open programs or browser tabs that you are not currently using to speed up QuickBooks Online.

Like all modern web-based apps, QBO and its performance depend on the following: the Computer’s processing power, amount of available RAM, and bandwidth of your internet connection.

See this article for more detailed steps and proceed to the How to improve performance section: Why is my QuickBooks Online slow?. It also includes video tutorials on how to run the speed test and its result.

However, if it's still running slow, we can do some of the basic troubleshooting steps by accessing your account in a private window.

Here's how:

• Google Chrome: Press CTRL + Shift + N.
• Safari: Press Command + Shift + N.
• Mozilla Firefox: Press CTRL + Shift + P.

Once signed in, run the report again. If it rectifies the issue, go back to your main browser and clear its cache to remove the portal's history. You may also try accessing your account using another supported browser.

For additional reference, you can use the following article to personalize a report, like adding extra details to the Header/Footer section, as well as how to save custom reports: Customize reports in QuickBooks Online.

Let me know the results after trying the steps above. I'm to here provide you with additional assistance if you need anything else. Have a good one.