ill give it a shot. if it keeps persisting ill try to get a video and pictures of whats going on.
Hey mr fish. It sounds like the line is coming out too fast. The spool jamming after 20' of line is happening after the birds nest has already occurred. If the spool jammed before a birds nest formed there wouldn’t be a birds nest because the spool needs to be spinning to get a birds nest. Just try using your thumb more on your casts to slow the line down and gradually increase the distance of your cast as you get better.