So glad it finally worked out
I would use about 7 stitches per inch in that polyester.
In your video they were much closer together
Keep working with the spring position and the tension until there is no continuous thread on top or bottom.
Since the thread goes left, from the tension discs, you may end up with the whole assembly turned so the pin is at 9:00 or so
The twist / knot should be inside the material and not showing on either side.
Glad we could help
Life's A Journey
It's not to arrive safely at the grave in a well preserved body,
But rather to skid in sideways, totally worn out, shouting,
Woo Hoo!....What a Ride!