Related field not updating


First off - sorry if this has been asked and answered before - I've looked but can't find anything ...

I have a Module 'Event Locations' which has a TextArea field, 'test refreshments'.
I have made a one-to-one relationship with Module 'Open Course Bookings' and created a field 'test refreshments' and in the Formula section have added 'related($eitev_locations_ocb_open_course_bookings_1,"refreshments_c")'

However it does not work - I have noticed that the Module is titled 'Event Locations' but the link is '$eitev_locations ....' (i didn't type it, it came from the Relate field dropdowns

Hope you can help