Likewise discovered that the sun position bore no relationship with the VW heliodon. It’s worth mentioning that in addition to using the shift+RHmouse control of time of day, you can use Ctrl+U or I to set the base angle and height. So - I’ve been setting time to 12:00 and then setting base angle and height to suit orientation / time of year, and then everything works - during that session anyway - although this all needs repeating each time Enscape is closed/re-opened. It would be really good if the link to the VW heliodon can be (re) made, although this work-around at least works.