We can refresh the system and see if the error is caused by a browser-related issue, useraysen-ilgazdag.
Good job for disconnecting and reconnecting the account. It's one way of refreshing the connection of your PayPal account to QuickBooks Online. There are times that the regular browser stores history or cache files that can cause unexpected behaviors of frequently visited sites.
We can verify and isolate the error by logging in to a private browser. Then, go to the Banking page to see if you're still prompted with the message. You might also want to disconnect and reconnect again from there. If everything looks fine as expected, switch back to the regular browser and clear the cache. Other supported browsers such as Google Chrome, Internet Explorer, or Mozilla Firefox can also help you get rid of the error.
For more details on how to manage your bank feeds, check out these articles:
I'll be around the corner if you have other questions. Have a great day and you stay safe always!