Most of the unusual behaviors can be fixed by clearing the browser’s cache. You can try using an incognito or a private browser to sort this out.
You can use these shortcut keys:
Google Chrome: Ctrl + Shift + N
Mozilla Firefox: Ctrl + Shift + P
Internet Explorer: Ctrl + Shift + P
Safari: Command + Shift + N
If it works, go back to your main browser to clear the cache so the system can start fresh. You can also use other browsers as an alternative since it uses a different cache storage folder on your computer.
For your future reference, let me share this article about organizing your QBO account: Help article.
Keep me posted if you have other concerns. I'll be around.