I am not familiar with your machine but were doing FMQ before using the WF?
On the BL machines, the hand wheel needs to be turned manually to re-engage the feed-dogs. Perhaps that is the issue with your machine. There is also a lever on my WF (BL machines).
Second suggestion is to check behind the WF and make sure the area is clear.
Does the WF plug into your machine? Make sue it is plugged in correctly. Last resort is to check the manual under troubleshooting. The tips might help solve the issue.
Good luck with the WF.