For some accounts they will require the owner to accept each individual tip because they are in a different currency or due to other regional restrictions.
You can solve this by changing some settings in your PayPal account. (The screenshots are using a PayPal business account)
1.Click on the profile icon in the top right and select "Profile and settings"
2.On the left sidebar click "My selling tools".
3.Next find the "Block payments" setting and press "update" on the right side.
4.Look for "Allow payments sent to me in a currency I do not hold" and set it to Yes, accept and convert them to U.S Dollars. (Or whatever default currency your PayPal account uses)