PayPal item_name不再发送项目描述

I had a dynamic PayPal URL which when clicked, would send users to PayPal where the Description, Price and Quantity were pre-populated.

For some reason though, it no longer works. If I try to send it with item_name and nothing sends, and I don't remember changing this value.

https://www.paypal.com/cgi-bin/webscr?cmd=_xclick&business=EMAIL&currency_code=GBP&amount=AMOUNT&return=RETURN_PATH&item_name=ITEM_NAME