I had similar timeout issue when I first install my VFD. My breakout board did not make contact with controller connector. At that time I noticed that I needed to apply pression on the breakout board to get OK status. During my test I was able to get it work while the nuts were removed. I finally replace both of them with shorter one (few mm) that were initially on my computer monitor.
So Check this:
A. First check if those nuts are fully tighten
B. Second, check if the metal part is near enough to the connector.
Good Luck