[cscott1]

For example When I want to enter a movie search name which is different to the filename. So from inside the skin I select edit name/sort name the long press the OK key on the remote. This brings up the Google speech to text search. I know this worked in a previous skin. 

OK so I'm not sure if this is Going to help you but if you press the microphone button from within the skin it opens up Google assistant. I just figured out that when using the virtual keyboard if you long press enter on the words English QWERTY it brings up the old voice to text works great try it. 

 I have never used Google Assistant inside a skin, I always press the OK button when I'm actually on the virtual keyboard.. Is that the one you are talking about?

Yes from within the virtual keyboard navigate to the words English QWERTY and long press the OK button. That will bring up the Google Voice to text bar at the top of the screen. I tested this on Android TV both Android 6 and 8 works. I believe you have to be running Kodi 18 for voice to text to work though.