Passing units of measure with conversions to container

[Richard Bellars]

Hello
Using webflow, I have a screen field for Unit of Measure with the standard
conversion on it so that, for example, the German unit 'ST' is converted to
'PC' on the screen.
The problem occurs when the values are passed to the container, where I get
the error "Unit ST is not created in language EN". In de-bug, I have tried
converting 'ST' to 'PC' to force the value through but this is not working.
Has anyone come across this before?
Any help/advice would be very much appreciated.
Best regards
Richard