I have the same problem with the bulk filament. It started taking it and then quit. Tried adjusting the pulley but I almost think it doesn't get hot enough to melt it. When the stock stuff is in there and you remove it and put the bulk in it works for a minute and then quits. Almost like the melted stock material help heat it until it's all gone. I can't really tell if the hack works or not since I can't get the bulk material to flow.