I see a lot of post with this problem and looks like it's not really solved. When I use DOpus for making upload with FTP, I'm stuck with a very slow speed (8mbit/s), the same server, same time with FileZilla, 700mbp/s. I tried to change the copy_buffer_size options but still the same. Why not using the FTP lib from filezilla ?
For me it's a very bad point for DOpus,I love this software but it's too bad to see this part forget.
Someone can help me or is it possible to fix it ? Thanks