Let's try checking if this has something to do with the browser, info253.
There are times overloaded files stored in your browser affects the process in QuickBooks Online (QBO). You can try logging into your account using a private or Incognito window.
If the Invoices page loads completely, you can clear your browser's cache to remove the temporary files or switch to other browsers.
If the same thing happens, I'd suggest contacting our Technical Support Team. They'll further investigate what's causing this issue.
Here's how to reach them:
In the meantime, you can use your QBO mobile app to access the invoices.
You can always reply to this post if you need anything else.