I've checked on our records and found an ongoing investigation about PayPal bank not syncing transactions to QuickBooks Online (QBO). Our engineers are now working to get a resolution as quickly as possible.
As of now, I encourage reaching out to our Support Team so you'll be added to the list of affected users and automatically receive email notification of the latest updates. To contact support, tap on Contact us from the Help menu.
On the other hand, disconnecting and reconnecting a bank account in QBO may cause duplicate entries. If you wish to, you can manually update your bank account to bring transaction any transactions that have cleared since the last automatic download.