I'm glad you've reached out to QuickBooks Community. Let me provide some insights about syncing PayPal account in QuickBooks Online (QBO).
We currently have an open investigation regarding the PayPal bank syncing problem with QuickBooks Online. Our online banking team is already investigating this issue and working for an immediate fix.
While we're continuing to work on resolving this issue, you can manually download the bank transactions from your bank website and import them into QBO using the WebConnect feature by following the steps in this article: How to upload more than 90 days of bank transactions.
If you need further assistance with the workaround steps, I recommend calling our QuickBooks Online Support Team. They have the tools to do a remote session and walk you through the process: