Problem(s) Encountered:

I couldn't get the dome to close! But then I managed to fix it by trial and error:

Solution:

tx slit close   [even though the dropleaf was open]

To my surprise, I could see the slit moving in the dome camera image.

Then:

tx slit stop    [I guessed at this, and it simply stopped while still almost wide open.]

tx dropleaf close   [It finally closed!]

tx slit close   [It continued closing, and closed.  Voila!]