This option will check and resolve any connection error between Paypal and QuickBooks Online. This also helps in bringing in your bank transactions. Go to Banking tab, select Paypal and click the Update.
I also checked our record and found a similar concern. Our engineers are working already to see why there are missing Paypal transactions. Please reach out to our Customer Support Team so you'll be added on the list of affected users. That way, they can gather more details about it that can help them resolve this issue. Simply go to Help and click Contact us.
For now, you can manually import your Paypal transactions using the webconnect file. You can get a copy of this file through your Paypal online account. Please refer to these articles: