I have a similar problem but it is intermittent. I am in China and the problem is NOT the great firewall of China. If I turn on my VPN, even using a Chinese server, it will work. The problem is my VPN is limited to 50 Gig a month,and I hate to waste bandwidth sharing.
Anyways, sometimes if I turn on my VPN I'll connect to the seeds and peers and then the download will continue with the VPN off. Other times I can only download with the VPN on. And other times I can download without a VPN at all. Yet lately I can only download with a VPN on.
Any suggestions? I do have GREEN LIGHT (for DHT connection) but a YELLOW light for blocked ports..