Since the Community is a public space, we can't directly specify if there's a problem with your PayPal's synchronisation with QuickBooks (QB), Kaye.
Please know that we don't have the specialised tools to verify this matter. We can only offer guidance on how to fix issues depending on their details or the customer's encountered situation.
To assist you appropriately, may I ask if there's a specific period on your PayPal entries that did not sync to QuickBooks? Or are you trying to connect your PayPal to accept customer payments and encountering error notification(s)? Providing answers to these questions could help us supply a precise resolution regarding this situation.
In the meantime, you can try checking if there's an issue on PayPal's end by connecting to their website or contacting their customer support team directly. If none, I suggest clearing your standard browser's cache and cookies to remove excessive data build-up that impacts the platform's performance.
If you encounter the same problem, consider using another supported browser to sync PayPal into QuickBooks.
I'm also attaching an article that can help you organise your transactions appropriately: Categorise transactions in QuickBooks Self-Employed.
Feel free to click the Reply button once you're ready to add additional details about your concern.