Put some tri-flow or sewing machine oil between the post/spindle and the winder housing (sorry I don't have the technical terms for those parts). Since you don't seem to have an oil hole there, put the oil as close as you can get it. If you have a syringe with a needle that would be helpful but isn't necessary. If the machine is not in a cab, you could tilt it a bit and that might let gravity help the oil flow into that crevice. Then just keep rotating the winder to help the oil move around and do its job. Don't get oil on the belt or the bobbin tire because oil degrades rubber. A lot of people use a hair dryer to speed things up, but I personally haven't tried that. I also use WD-40 or liquid wrench in situations like this, but others might disagree. (Be careful not to get either of those on rubber parts, either).
Did you check the belt tension? Because even if it's not causing your problem, it's important that it's not too tight. Rain's video is about what to do when the needle still moves after you turn the stop-motion knob. Are you having that problem too?