Thanks for posting in the Community, @viviankbk. I'm here to help with running your P&L report.
@Lexiesmemere is correct that it's often recommended to try browser troubleshooting, such as using an incognito window or clearing cache. Temporary internet files and cache are stored in order to increase loading times and performance. However, too much can accumulate and interfere with processes in QuickBooks Online and cause unexpected behavior. I'm including an article which provides additional insight into this, as well as the steps: How Do I Clear My Browser Cache and Temporary Internet Files?.
Additionally, I recommend seeing if you can run other reports or if it's just the Profit and Loss that's not loading correctly. This will help to isolate the behavior.
I'm confident that this will help to get you on the right path.
Please feel free to let me know how it goes by posting a comment below. Have a good day.