Let's clear the cache stored on your desktop app so you can open a new tab and get you back on track. Let me show you how.
If the issue persists even after following the steps above, consider deleting the app and reinstalling the file again using the file downloaded from this article: What can I do with the QuickBooks App for QBO?
Please know that the article included above is base on the US version of the QuickBooks Online app. But the same content applies to the current version and region you're working with.
Additionally, I've also included this reference for a compilation of articles you can use while working with us: Help Articles for QuickBooks Online.
If there's anything else that I can help you with, please let me know in the comments below. I'll be here to lend a hand.