I wouldn't worry about it. Just apply to all 3 and make sure you are up to date with all 3. VNA probably doesn't see any names until you are actually hired by the contractor and VNA just rubber stamp the names.
You could also contact each contractor to see what is going on. They all want your business because they will makes lots of money off you for the duration of your contract.
If it has only been 2 or 3 months it may be normal. Things don't happen overnight.
I don't work there anymore, but I believe that is the way it is still done.