OK - the HOTT switches are animated and require a lot more work than simple non-animated ones. I just gave myself a "crash" course in using them and have encountered the same problem.
From what I could see and achieve, you need to add a HOTT junction object from the scenery tab to the track, then use invisible track (e.g. JK Junction wire (blue) or (green) or (grey)) to join the yellow diamonds, then add and orientate the HOTT switch itself.
At that point I can only get the double sided red arrow, not the green and red of a working switch so I am obviously missing something.
I did a search of the forum for HOTT and did not find anything useful that was in English.
The original JK animated switches that I used in 2006, 2009 and 2010 do not work in TS12.
So more help is needed from someone with experience please.
Peter Ware