Welcome and thanks for dropping by the Community, @harmoniousbalanc.
To check if the browser's cache and cookies are causing this odd behavior, try signing into your QuickBooks Online (QBO) using a private browser (incognito).
Here's how:
- Press Ctrl + Shift + N (Google Chrome).
- Ctrl + Shift + P (Firefox).
- Control + Option + P (Safari).
Once logged in, try to change the dates on the Profit and Loss report.
If it's successful, return to your default browser and perform a clear cache to refresh the system. However, if the issue persists, try using other supported browsers.
To learn more about customising Profit and Loss and other reports in QBO, I highly suggest checking out these articles:
Please leave a comment in this thread if you have any other issues or concerns. I'll be more than willing to assist. Have a good one!